Comparison Nokia 2720 Flip 4 GB / 2 SIM vs Nokia 800 Tough 4 GB / 0.5 GB

Characteristics of the main (and most often the only) display installed in the device.

In addition to the basic properties - such as size, resolution (according to it, screens are conventionally divided into HD, Full HD, 2K and more), sensor type (most often IPS, OLED, AMOLED, Super AMOLED, Dynamic AMOLED,), this list can more specific features. Among them are the shape of the surface ( flat or curved), the presence and version of the Gorilla Glass coating (including the top v6 and Victus), HDR support and the refresh rate (a frequency on top 60 Hz is considered high, namely 90 Hz, 120 Hz and 144 Hz) . Here is a more detailed description of the characteristics relevant to modern displays:

- Size. Traditionally, the screen size is indicated in inches. A larger display is more convenient to use: more information is placed on i...t, and the image itself is better readable. The downside of increasing the size is an increase in the dimensions of the device. Today, smartphones with screens of 5" or less are considered small. 5.6 - 6" and up to 6.5" is already a medium format. Also, many modern models have a size of 6.5". Classic phones without touch screens do not need a large size - in them it usually does not exceed 3".

- Permission. Screen resolution is specified based on its vertical and horizontal dimensions in dots (pixels). The larger these dimensions (with the same size) - the more detailed and smoothed the picture looks and the less individual pixels are visible on it. On the other hand, increasing the resolution increases both the cost of the display itself and the requirements for the phone's hardware. It is also worth noting that the same resolution on screens of different sizes looks different; so when evaluating detail, it is worth considering not only this parameter, but also the PPI number (see below).

— PPI. The density of dots (pixels) on the screen of the device. It is indicated by the number of dots per " (points per ") - the number of pixels for each horizontal or vertical segment of 1 ". This indicator depends both on the size and resolution, but in the end it is the PPI number that determines how smooth and detailed the image on the display is. For comparison, we note that at a distance of about 25 - 30 cm from the eyes, a density of 300 PPI or more makes individual pixels almost invisible to a person with normal vision, the picture is perceived as a complete one; at greater distances, a similar effect is noticeable at a lower point density.

— Matrix type. The technology by which the screen sensor is made. This parameter is indicated only for relatively advanced displays that are superior in performance to the simplest LCD screens of push-button phones. The most widespread in our time are the following types of matrices:

• IPS. The most popular technology for the screens of modern smartphones. It provides a very decent image quality, viewing angles and response speed, although it is somewhat inferior in these parameters to many more advanced options (see below). On the other hand, IPS also has important advantages: durability, uniform wear, and also a rather low cost. Thanks to this, such screens can be found in all categories of smartphones - from low-cost to top-end.
• AMOLED. Organic light-emitting diode (OLED) sensor technology developed by Samsung. One of the key differences between such matrices and more traditional displays is that they do not require external illumination: each pixel is its own light source. Because of this, the power consumption of such a screen depends on the characteristics of the displayed image, but in general it turns out to be quite low. In addition, AMOLED matrices are distinguished by wide viewing angles, excellent brightness and contrast ratios, high color reproduction quality and fast response time. Due to this, such screens continue to be used in modern smartphones, despite the emergence of more advanced technologies; they can be found even in top-end models. The main disadvantage of this technology is the relatively high cost and uneven wear of the pixels: dots that work longer and more often at high brightness burn out faster. However, usually this effect becomes noticeable only after several years of intensive use - a period comparable to the operational resource of the smartphone itself.
• AMOLED (LTPO). An advanced version of AMOLED panels with the ability to dynamically adjust the refresh rate depending on the tasks performed. The abbreviation LTPO stands for Low Temperature Polycrystalline Oxide. Behind this term is a combination of traditional LTPS technology and a thin layer of TFT oxide film with the addition of hybrid-oxide polycrystalline silicon to drive the sweep switching circuits. AMOLED panels (LTPO) reduce the energy consumption of the gadget by an order of magnitude. So, when performing active actions, the device screen uses the maximum or high refresh rate, and while viewing pictures or reading text, the display reduces the rate to a minimum.
• Super AMOLED. An improved version of the AMOLED technology described on top One of the key improvements is that in Super AMOLED screens there is no air gap between the touch layer and the display located under it. This made it possible to further increase the brightness and image quality, increase the speed and reliability of the sensor response and at the same time reduce power consumption. The disadvantages of such matrices are the same as the original AMOLED. In general, they are quite widespread; most smartphones with similar screens belong to the middle and top categories, but there are also low-cost models.
• OLED. Various types of matrices based on the use of organic light emitting diodes; in fact - analogues of AMOLED and Super AMOLED, produced not by Samsung, but by other companies. The specific features of such screens may be different, but for the most part they are, on the one hand, more expensive than popular IPS, on the other hand, they provide higher image quality (including brightness, contrast, viewing angles and color fidelity), and also consume less energy and have small thickness. The main disadvantages of OLED screens are the high price (which, however, is constantly decreasing as the technology develops and improves), as well as the susceptibility of organic pixels to burn-in when broadcasting static images for a long time or images with static elements (notification panel, on-screen buttons, etc.). ).
• OLED (polymer). Organic Light-Emitting Diode (OLED) screens, which do not use glass as a base, but a transparent polymer material. We emphasize that we are talking about the basis of the sensor; from on top it is covered with the same glass as in other types of screens. However, this design offers a number of advantages over traditional "glass" matrices: it provides additional impact resistance and is great for creating curved displays. On the other hand, in terms of optical properties, plastic still falls short of glass; so screens of this type are often inferior in image quality to their “peers” made using traditional OLED technology, and with a similar picture quality, they are noticeably more expensive.
• OLED (LTPO). OLED-matrices with adaptive refresh rate, which can be changed in a wide range based on the tasks performed. In games, screens with LTPO technology automatically raise the refresh rate to the maximum values, while viewing static images, they reduce it to a minimum (from 1 Hz). At the heart of the technology is a traditional LTPS substrate with a thin TFT oxide film on top of the TFT base. The ability to control the flow of electrons provides dynamic control over the refresh rate. The competitive advantage of OLED (LTPO) is reduced power consumption.

In addition, screens in modern smartphones can be made using the following technologies:

• pls. A variation of IPS technology created by Samsung. In some respects - in particular, brightness, contrast and viewing angles - it surpasses the original, while it is cheaper to manufacture and allows you to create flexible displays. However, for a number of reasons, it is not particularly popular.
• Super AMOLED Plus. A further development of the Super AMOLED technology described on top. Allows you to create even brighter, more contrasting and at the same time thin and energy-efficient screens. However, most often such screens in our time are simply referred to as "Super AMOLED", without the "Plus" prefix.
• Dynamic AMOLED. Another AMOLED improvement introduced in 2019. The main features of such matrices are increased brightness without a significant increase in power consumption, as well as 100% coverage of the DCI-P3 color space and compatibility with HDR10 +; the last two points, in particular, make it possible to reproduce modern high-low-cost cinema on such screens with the highest quality. The main disadvantage of Dynamic AMOLED is traditional - the high price; so such matrices are found mainly in top models.
• Super Clear TFT. A joint development by Samsung and Sony, which appeared as a forced alternative to Super AMOLED matrices (the demand for them at one time significantly exceeded production capabilities). True, the image quality of Super Clear TFT is somewhat lower - but in production such matrices are noticeably simpler and cheaper, but in terms of performance they still surpass most IPS screens. However, in our time, this technology is rare, giving way to AMOLED in different versions.
• super LCD. Another alternative to various kinds of AMOLED technology; used mainly in HTC smartphones. Similar to Super AMOLED, such screens do not have an extra air gap, which has a positive effect on both image quality and the clarity of sensor responses. A notable advantage of the Super LCD is its good power efficiency, especially when displaying bright whites; but in terms of overall color saturation (including black), this technology is noticeably inferior to AMOLED.
• LTPS. An advanced type of TFT matrices, created on the basis of the so-called. low temperature polycrystalline silicon. It allows you to easily create screens with a very high pixel density (more than 500 PPI - see on top), achieving high resolutions even with a small size. In addition, part of the control electronics can be built directly into the sensor, reducing the overall thickness of the display. The main disadvantage of LTPS is the relatively high cost, but nowadays such screens can be found even in low-cost smartphones.
• S-PureLED. A technology developed by Sharp and used primarily in its smartphones. Actually, the technology of the matrices themselves in this case is called S-CG Silicon TFT, and S-PureLED is the name of a special layer used to increase transparency. S-CG Silicon TFT is positioned by the creators as a modification of the LTPS technology described on top, which allows to further increase the resolution of the display and at the same time build more control electronics into it (up to a whole “processor on glass”) without increasing the thickness. Of course, these screens are not cheap.
• e-ink. Matrices based on the so-called "electronic ink" - a technology common primarily in electronic books. The main feature of such a screen is that during its operation, energy is spent only on changing the image; a still picture does not require power and can remain on the display even in the absence of power. In addition, by default, E-Ink matrices do not glow on their own, but reflect outside light - so their own backlight is not necessary for them (although it can be provided for work at dusk and darkness). All this provides a solid energy savings; and for some users, such screens are purely subjectively more comfortable and less tiring than traditional matrices. On the other hand, E-Ink technology also has serious drawbacks - first of all, a long response time, as well as the complexity and high cost of color displays, combined with poor color reproduction quality on them. In light of this, in smartphones, such matrices are a very rare and exotic option.

— Sweep frequency. The maximum display refresh rate, in other words, the highest frame rate that it can effectively reproduce. The higher this figure, the smoother and smoother the image is, the less noticeable the “slideshow effect” and blurring of objects when moving on the screen. At the same time, it should be borne in mind that the refresh rate of 60 Hz, supported by almost any modern smartphone, is quite sufficient for most tasks; even high-definition videos hardly make use of high frame rates these days. Therefore, the scanning frequency in our catalog is specially specified mainly for screens capable of delivering more than 60 Hz (in some models - up to 240 Hz). Such a high frequency can be useful in games and some other tasks, it also improves the overall experience of the OS interface and applications - moving elements in such interfaces move as smoothly as possible and without blurring.

HDR. A technology that allows you to expand the dynamic range of the screen. In this case, the range of brightness is implied - simply put, the presence of HDR allows the screen to display brighter whites and darker blacks than on displays without support for this technology. In practice, this gives a noticeable improvement in image quality: the saturation and reliability of the transmission of various colors improves, and the details in very light or very dark areas of the frame do not “sink” in white or black. However, all these advantages become noticeable only on the condition that the content being played is originally recorded in HDR. Nowadays, several varieties of this technology are used, here are their features:

• HDR10. Historically the first of the consumer HDR formats, it is extremely popular today: in particular, it is supported by almost all streaming services with HDR content and is standardly used for such content on Blu-ray discs. Provides a color depth of 10 bits (more than a billion shades). At the same time, HDR10+ format content (see below) can also be played on devices with this technology, except that its quality will be limited by the capabilities of the original HDR10.
• HDR10+. An improved version of HDR10. With the same color depth (10 bits), it uses the so-called dynamic metadata, which allows transmitting information about the color depth not only for groups of several frames, but also for individual frames. This results in an additional improvement in color reproduction.
• Dolby vision. An advanced standard used particularly in professional cinematography. It allows you to achieve a color depth of 12 bits (almost 69 billion shades), uses the dynamic metadata mentioned on top, and also makes it possible to transmit two image options at once in one video stream - HDR and normal (SDR). At the same time, Dolby Vision is based on the same technology as HDR10, so in modern electronics this format is often combined with HDR10 or HDR10 +.

- DC Dimming support. Literally from English, Direct Current Dimming is translated as direct current dimming. This technology is designed to minimize flicker in OLED and AMOLED screens, which, in turn, reduces the load on the user's visual apparatus and protects eyesight. The “flicker-free” effect is achieved by directly controlling the brightness of the backlight LEDs by changing the voltage applied to them. Due to this, a decrease in the intensity of the glow of the screen is ensured.

- Curved screen. A screen that has curved edges to which the displayed image extends. In other words, in this case, not only glass is curved, but also part of the active sensor. Displays where both edges are curved are sometimes referred to as "2.5D glass" as well; also there are devices where the screen is bent only on one side. In any case, this feature gives the smartphone an interesting appearance and improves the visibility of the image from some angles, but it significantly affects the cost and can create inconvenience when holding (especially without a case). So before buying a model with such equipment, ideally, you should hold the device in your hand and make sure that it is comfortable enough.

- Gorilla Glass. Special high-strength glass used as a display cover. It is characterized by endurance and resistance to scratches, many times superior to ordinary glass in these indicators. It is widely used in smartphones, where large screen sizes put forward increased requirements for coverage reliability. Modern phones may have different versions of this glass, here are the features of different options:

• Gorilla Glass v3. The oldest of the current versions is released in 2013; now found mainly among inexpensive or obsolete devices. However, this coating also has undoubted advantages: this is the first generation of Gorilla Glass, where the creators have made a noticeable emphasis on resistance to scratches from keys, coins and other objects that the phone can “collide” in a pocket or bag. In this respect, the v3 version remained unsurpassed until the release of Gorilla Glass Victus in 2020.
• Gorilla Glass v4. Version released in 2014. A key feature was that the development of this coating focused on impact resistance (whereas previous generations focused mainly on scratch resistance). As a result, the glass is twice as strong as in version 3, despite the fact that its thickness is only 0.4 mm. But here's the scratch resistance, compared with its predecessor, has decreased slightly.
• Gorilla Glass v5. A gorilla improvement released in 2016 to further improve impact resistance. According to the developers, the glass of the v5 version is 1.8 times stronger than its predecessor, remaining intact in 80% of drops from a height of 1.6 m "face down" on a rough surface (and guaranteed impact resistance is 1.2 m). Scratch resistance has also improved somewhat, but this material still falls short of v3 performance.
• Gorilla Glass v6. Version introduced in 2018. For this coating, a 2-fold increase in strength compared to its predecessors is claimed, as well as the ability to endure multiple drops on a hard surface (in tests, v6 glass successfully endured 15 drops from a height of 1 m). The maximum drop height (single) with guaranteed integrity is declared at 1.6 m. Scratch resistance has received practically no improvement.
• Gorilla Glass 7. Original name for Gorilla Glass Victus - see below.
• Gorilla Glass Victus. The "heir" of Gorilla Glass 6, released in the summer of 2020. In this coating, the creators paid attention not only to increasing the overall strength, but also to improving scratch resistance. According to the latter indicator, Victus surpasses even the v3 version, not to mention more sensitive materials (and compared to v6, scratch resistance is claimed to be twice as high). As for durability, it allows you to guarantee to endure single drops from a height of up to 2 m, as well as up to 20 consecutive drops from a height of 1 m.

Second display, in addition to the main one. Features of such a display depend on a number of specs of the device itself. For example, in clamshell phones, an additional screen allows you to receive notifications about received messages, incoming calls, etc., without opening the phone once again and without wearing out the rotary mechanism. And in modern smartphones, the second display can be "electronic paper"; it is used for simple tasks like reading books or mail, though it can significantly save battery power. At the same time, clamshell phones are practically out of use today, and installing a second screen in a smartphone significantly complicates the design and increases its cost. Therefore, this feature is not very popular.

The most popular nowadays are chips from Qualcomm and MediaTek, CPUs from Unisoc are slightly less common. Qualcomm has several processors of each series, namely Snapdragon 765G, Snapdragon 778G, Snapdragon 7 Gen 1, Snapdragon 7+ Gen 2, Snapdragon 7 Gen 3, Snapdragon 865, Snapdragon 870, Snapdragon 888, Snapdragon 8 Gen 1, Snapdragon 8+ Gen 1, Snapdragon 8 Gen 2, Snapdragon 8 Gen 3. And Mediatek has a low cost series MediaTek Helio P and a line of advanced chipsets MediaTek Dimensity (Dimensity 1000, Dimensity 8000, Dimensity 9000).

Knowing the name of the CPU model installed in the smartphone, you can find detailed data on a particular CPU and evaluate its level and general capabilities. This is especially true in light of the fact that these capabilities depend not only on the number of cores a...nd clock speed, but also on the specific nuances of the design.

The quantity and types of removable cards (SIM, memory cards) that can be installed in the phone. On E-Catalog this parameter is specified only for devices that allow the installation of more than one SIM card — most often that means 2 SIM cards, however, you can find devices with three or even four corresponding slots.

Initially several slots mean that several phone numbers can be used on one device. Thus it is possible to combine personal and work numbers, separate plans for calls and the Internet, etc. in one device. However modern devices (especially smartphones) often provide the combined design “SIM + SIM / memory card " : one of the slots is intended only for SIM, the second can be used both for a SIM card or for a memory card such as microSD or Nano Memory (see "Memory card slot"). At the same time, there is no separate slot for a memory card in the device, so the user has to choose between the second number and additional storage. Therefore, if you want to use 2 SIM cards and a memory card at the same time, you should pay attention to models where this is directly stated.

It is also worth considering that individual slots may differ in the type of compatible SIM cards; see below for details.

Inputs and outputs of the smartphone.

This paragraph usually specifies the type of charging and data port (most often it's USB-C), and whether the smartphone has a mini-jack (3.5 mm)(there are devices without it). It can also indicate the interface of the USB-C port up to the high-speed third version ( USB-C v 3), the location of the 3.5 mm jack (headphone output) and additional ports for a more specific purpose.

The main ports are used primarily for charging the battery, for connecting various accessories to the phone and for connecting the device itself to the computer via a cable. 3.5 mm port (mini-Jack) is intended primarily for headphones and other audio accessories, although other usage formats are possible. Here is a more detailed description of the different types of connectors:

— USB-C. A relatively new type of universal interface, a kind of successor to microUSB, which is increasingly used in mobile devices. USB-C differs from its predecessor primarily in slightly larger dimensions and a convenient two-sided design: thanks to it, it does not matter which side to insert the plug. In addition, this interface allows you to implement more advanced functions than microUSB — in particular, certain fast charging technologies were originally created specifically for USB-C. USB standard supported by this ty...pe of connector can be specified separately. Today the options are:

• USB-C 3.2 gen1. The standard formerly known as USB 3.0 and USB 3.1 gen1. Provides data transfer rates up to 4.8 Gbps.
• USB-C 3.2 gen2. The current name for the standard, formerly USB 3.1, then USB 3.1 gen2. The connection speed on this interface can reach 10 Gbps.
• USB-C 3.2 gen2x2. A standard (formerly known as USB 3.2) that delivers twice the speed of "regular" USB 3.2 gen2, up to 20Gbps. Unlike previous versions, it was created specifically for the USB-C connector.

— microUSB. A universal connector, which formerly was extremely widely used in portable devices (with the exception of Apple devices). It is less convenient and technically advanced than USB-C, therefore it is gradually losing popularity; however, there are still quite a few devices with microUSB out there.

— Lightning. Apple's proprietary connector used exclusively in the iPhone. It has a double-sided design that allows you to connect the plug in either direction. In modern iPhones, it is used both as a universal one and for connecting headphones (in 2016, Apple abandoned the 3.5 mm audio output in their smartphones).

— Original port. The one that does not belong to the types described above. Nowadays, such solutions are extremely rare — standard interfaces are more convenient and versatile, as they allow you to use not only "native" accessories, but also solutions from third-party manufacturers.

— USB A. Full-size USB port — similar to those used in PCs and laptops for connecting various peripherals. It has a similar purpose in phones, it is mainly used for flash drives and other external accessories (the specific set of supported devices should be specified separately). Usually, it is supplemented with a more traditional universal connector like microUSB or USB-C; in general, for a number of reasons, it is very rare.

— Magnetic connector. A connector that uses a permanent magnet instead of a standard plug system to hold the cable. Such solutions are used mainly in devices with water protection (see "Waterproof"), and most often — to charge the battery in addition to standard universal connectors (usually microUSB or USB-C). The main convenience of the magnetic connector is that it does not need plugs to protect it from water. It simplifies the connection and disconnection of the charger, and secondly, the wear of the plugs on standard ports is minimized — they do not need to be opened and closed every time you charge the smartphone. However only a special “native” cable is suitable for a magnetic connector; but if this cable is lost or broken, it may be possible to charge in the usual way, through a traditional universal connector.

— Mods contacts. Contacts for connecting special additional modules that expand the functionality of the device. Such equipment is usually found in some rugged phones. The modules themselves are usually a kind of "cases" that are put on the back of a smartphone; in such a “case” there may be, for example, an additional battery, a gamepad or even a thermal vision mod.

— Mini-jack (3.5 mm). A connector primarily used to connect wired headphones and other audio devices (such as portable wired speakers). Such a connection is extremely popular among audio accessories (and not only for "mobile" purposes); so finding headphones, a headset or speakers for this connector is usually not a problem. In addition, the 3.5 mm jack can also be used for more specific tasks — for example, connecting a selfie stick, a card reader or exchanging data with wearable fitness sensors and other specific equipment. However, such features are rarely used and require the installation of special applications, but connecting headphones is the initial function of such a connector, available by default. So the mini-jack connector is often called the "headphone output".

— Location of the headphone output. The 3.5 mm output described above in modern phones can be located on the top, bottom or side of the device. However, the latter option is generally less convenient than the first two, and therefore is rare. And the choice for this indicator depends primarily on how exactly you are going to carry the phone and which side will be used to connect headphones to it; For different situations, the options will also be different.

Additional features and capabilities of the device.

In modern mobile phones (especially smartphones) a very extensive amount of additional features can be provided. These can be both already familiar features, many of which are directly related to the original purpose of the device, as well as fairly new and/or unusual ones. The first category includes an emergency call button(often found on phones for the elderly), noise cancellation, FM receiver, notification light and a light sensor. The second category includes a face and fingerprint scanner (the latter can be located on the back cover, side panel, front and even right under the screen), gyroscope, advanced full-fledged flashlight, stereo sound, 3D surround sound, Hi-Res Audio and even such exotics as a barometer. Here is a more detailed description of each of these options:

— Face scanner (FaceID). A sp...ecial technology for recognizing the user's face — not just by photographing, but by building a three-dimensional model of the face based on data from a special module on the front panel. This technology is constantly being improved, nowadays it is able to take into account the change of hairstyles and facial hair, the presence of glasses, makeup, etc. At the same time, the recognition of twins and children's faces still remains weak points (they have fewer individual features than adults ). The main use of a face scanner is authentication when unlocking a smartphone, entering applications, making payments, etc. At the same time, other, more original use cases are possible. For example, in some applications, the face scanner reads the user's facial expressions, and then this facial expression is repeated by an emoji on the phone screen.

— Fingerprint scanner. Fingerprint reader. It is mainly used for user authorization - for example, when unlocking the device, entering certain applications or accounts, confirming payments, etc. As for placement options, fingerprint scanners are increasingly moving from the back cover of the device to the surface of the side power / unlock button - to You can touch the sensor on the side with your thumb without releasing the smartphone from your hands and practically without changing your grip. Some time ago, sensors on the front of the case were quite popular - in particular, thanks to Apple, which was the first to tightly implement fingerprint recognition in its gadgets. However, such placement inevitably increases the size of the bottom frame, so the front fingerprint scanner is rare in modern smartphones. A good alternative to it is scanners right on the screen (more precisely, under the display matrix), which do not take up extra space on the front panel.

— Stereo sound. The ability to play full stereo sound through your phone's own speakers, without external audio devices. There must be at least two speakers for this task. This complicates the design and increases its cost, but it has a positive effect on the sound quality: the sound is more expressive and detailed than when using a single speaker, it has a volume effect, as well as a higher volume.

– 3D surround sound. The mechanics of spatial surround sound with localization of sound sources in three-dimensional space allows you to deeply immerse yourself in the atmosphere of films, enjoy listening to audio tracks, or completely immerse yourself in mobile gameplay. Algorithms for implementing 3D sound in smartphones differ in terms of software and hardware support, but they are all aimed at achieving the effect of realistic sound stage. Note that support for 3D surround sound can mean both commonly used technologies such as Dolby Atmos or DTS:X Ultra, as well as proprietary solutions from individual audio brands that have a hand in the sound subsystem of a mobile device (AKG, JBL, Harman, Huawei / Honor Histen, etc.).

– Hi-Res Audio. Mobile device support for high-resolution audio Hi-Res Audio - a digital signal with parameters from 96 kHz / 24 bits. Audio tracks in this format sound as close as possible to the original ideas of the authors of the compositions. The result is a sound that is as close as possible to what was recorded in the studio.

— FM receiver. Built-in module for receiving radio stations broadcasting in the FM band. Some devices also support other bands, but FM is the most popular nowadays (due to the ability to transmit stereo sound), it is in it that music radio stations usually broadcast. Note that some devices for reliable reception may require the connection of wired headphones — their cable plays the role of an external antenna.

— Notification indicator. Physically separate light beacon, pulsating or being constantly lighted up in response to incoming notifications of missed calls and received messages (including the ones from instant messengers and social network clients). Also, the indicator light usually signals a low remaining battery level and lights up during the battery recharging. The implementation of the notification indicator can be different: for some phones it is single-colour, for others it has colour coding of signals, flexibly adjustable for certain events through the settings menu. The light beacon allows you to visually comprehend the presence of incoming notifications without having to turn on the smartphone screen.

— Emergency call button. A separate button designed for use in critical situations. The specific features of such a button may be different, depending on the model: sending “alarming” SMS to selected numbers, automatically receiving calls from these numbers or calling them in turn, turning on the siren, etc. Anyway, the “emergency” button is usually clearly visible, and its presence is especially useful if the phone is used by an elderly person (in fact, in specialized devices designed for elderly, this button is almost mandatory).

— Noise suppression. An electronic filter that cleans the user's voice from extraneous noise (sounds of the street, the rumble of the wind in the microphone grille, etc.). Thus, the person at the other end of the line hears only the voice, with virtually no extra sounds. Of course, no noise reduction system is perfect; however, in most cases, this feature significantly improves the quality of the speech transmitted by the phone to the other person.

— Gyroscope. A device that tracks the rotation of a mobile phone in space. Modern gyroscopes, usually, work on all three axes and are able to recognize both the angle and the rate of turn; in addition, this feature almost necessarily means the presence of an accelerometer, which allows (among other things) to detect tremors and sharp movements of the device.

— Full-fledged flashlight. The presence of an advanced flashlight in the phone — more powerful than the usual one. The specific design and capabilities of such a flashlight may be different. So, in some devices, a separate LED (or a set of LEDs) is provided on the upper end, and this light source is used only as a flashlight. In others (mainly smartphones), we are talking about a special design of the flash: it consists of several LEDs, and only a part of them is usually used to illuminate when shooting, and all at once to work in flashlight mode. And the additional features of such a light source may include a laser pointer, beam focus, brightness control, etc. Anyway, most models with this feature are rugged devices with increased resistance to dust, moisture and shock (however, there are exceptions).

— Light sensor. A sensor that monitors the level of ambient light. It is mainly used to automatically adjust the brightness of the screen: in bright ambient light, it increases so that the image remains visible, and in twilight and darkness it decreases, which saves battery power and reduces eye fatigue.

— Barometer. Sensor for measuring atmospheric pressure. By itself, the barometer only determines this pressure at the current time, but the methods of using such data may be different, depending on the software installed on the phone. For example, some navigation applications can determine the elevation difference between individual points on the ground by the difference in atmospheric pressure at these points; and in weather programs, barometer data can improve the accuracy of weather forecasts. Also, this feature will be useful for weather-sensitive people: it signals a change in the weather, allowing you to more accurately determine the cause of ailments and take measures to eliminate them.

The capacity of the battery that the mobile phone is equipped with.

Theoretically, the high capacity of the battery allows the device to work longer on one charge. However, actual battery life time will also depend on the power consumption of the gadget — and it is determined by the hardware specs, the operating system, special solutions provided in the design, etc. So in fact, phones with capacious batteries in general have "long battery life”, however, the actual battery life can differ markedly even for two models with similar specifisations. Therefore, for an accurate assessment, it is better to focus not on the battery capacity, but on the operating time in different modes directly claimed by the manufacturer (see below).

— Monoblock. The body is one single piece. The most suitable option for models with a touch screen, however, it is also very popular in push-button devices — monoblocks themselves are inexpensive, but at the same time they are very reliable, convenient, practical and go well with almost all the features of modern mobile phones. In addition, such cases can be quite thin. So, among modern smartphones(almost all of which are monoblocks) there are models with a depth of 8 mm, 7 mm and even 6 mm or less. 9 mm is considered a significant depth, and values of 10 mm or more are typical mainly for devices where a large depth is indispensable, such as shock-resistant models in reinforced cases, as well as smartphones with very high-capacity batteries.

— Folding. The case, which opens when used, is similar to a book or shell flaps: on one half of the “clamshell” there is a screen on the inside, and a numeric keypad on the other. Separately, we note that such phones should not be confused with models that have a foldable screen.

— Foldable screen. A rather unusual type of housing found in several smartphones. Such devices usually consist of two wings, like the "clams...hells" described above; however, they can be folded either horizontally or vertically (depending on the phone model), and the screen occupies both halves of the case at once and bends when folded. When folded, the screen can be located both inside and outside the device (in the first case, another display can be installed from the outside, allowing you to use the main features of a smartphone when folded). Anyway, this layout allows you to achieve a much larger display size than in monoblocks, and at the same time maintain compactness and ease of carrying. On the other hand, foldable screens are complex and expensive, and therefore they are used extremely rarely, mainly in top-tier devices.

— Slider. Such a body consists of two parts capable of sliding relatively to each other. In the classic slider, the top part, with the screen and navigation buttons, slides up to reveal the keyboard. The main advantage of sliders compared to monoblocks is compactness, and the disadvantages are increased depth and lower reliability due to the gradual wear of the opening mechanism. In modern smartphones, such a case is practically never found, and in phones it is gradually “leaving the stage”.

— Side slider. A kind of slider (see above), in which the upper half of the body, when opened, does not move up, but to the side. This option was used in early smartphones, because it allowed to combine a large display and a convenient QWERTY keyboard in one device (see "Data input"); but with the development of touch screens and their increase in size, it has lost its relevance.

— Double sided slider. A kind of slider (see above), in which the upper part of the body can move both up and down. When moving up, it usually opens the numeric keypad, and when moving down, additional stuff, such as player control buttons or built-in speakers. Due to the complexity and high cost, such cases were not widely used.

— Rotary. Quite an original case type, including two varieties. The first option is similar to a slider, but when opening / closing, the body halves do not move, but rotate relative to each other, similar to how it happens with the hands of a clock. All their advantages and disadvantages are similar to the same sliders, but they often differ in their original design. The second variety resembles an ordinary monoblock, but the lower part of the case in such models is able to rotate around the longitudinal axis of the device. Due to this, when turning the part under the screen, instead of a numeric keypad, there are special controls (most often the player control buttons). Due to the high cost and excessive complexity, this option is almost never used today.

The presence of water protection of the device; also in this paragraph, the specific level of such protection according to the IP standard is usually specified — for example, models with indicators IP67, IP68 and IP69 are classified as waterproof. The last two levels IP68/IP69K often coexist - devices with the “69th” protection rank are a priori protected according to the “68th” requirements.

The two digits in the IP designation indicate the levels of protection against adverse factors. At the same time, water protection is directly indicated by the last digit, but the first characterizes the level of resistance to dust and other contaminants. In modern mobile phones, you can find the following levels of protection:

5 — dust resistance (dust can get inside in small quantities that do not affect the operation of the device);
6 — dust protection (dust does not penetrate inside at all).

Lower levels of protection in mobile phones are not indicated (such device will no longer be dustproof, and there is no need to specify its specs). However, there are models that have an X instead of first digit — for example, IPX7. This means that this device has not been certified for dustproofing, although in fact the level of such protection can be quite high. So, in our example, moisture resistance of 7 means the poss...ibility of complete immersion in water, which means that such a case is closed very tightly from dust too.

As for moisture resistance, here the options:

— 2. The minimum level specified for mobile phones is protection from drops and splashes at an angle of up to 15° from the operating position of the device (usually screen up). Allows you to withstand moderate rain without strong winds.
— 3. Protection against drops at an angle up to 60° (medium rain with strong wind against the screen position).
— 4. Protection against splashes from any direction (rain with strong wind regardless of the position).
— 5. Protection against water jets from any direction (showers, storms).
— 6. Protection against wave impacts and strong water jets.
— 7. The minimum level that should be considered real water resistance. Allows you to endure short-term (up to half an hour) immersion under water to a depth of 1 m.
— 8. Possibility of long-term (30 minutes or more) immersion to a depth of more than 1 m, with continuous work in the immersed state. Specific depth and time limits may vary.
— 9. Protection against high temperature water jets (possibility of intensive washing with hot water under high pressure).

In general, a higher level of protection, on the one hand, provides an additional guarantee in case of adverse situations, on the other hand, it affects at least the price, and often also the dimensions and weight of the device. Also note that a waterproof phones can also be made shockproof (see below) — this is not necessary, but it is often found in models designed for use in extreme conditions.