Comparison Logitech Corded Keyboard K280e vs Logitech Wireless Keyboard K270

— Wired. Connection using a cable with one or another type of connector — most often USB, less often PS/2 or a proprietary plug (see "Connection interface"). Wired keyboards are notable for their low cost and overall convenience — in the sense that they do not require batteries and the operating time is unlimited. However the wire limits mobility; however, given that most often the keyboard is used in close proximity to the computer, this shortcoming cannot be called critical.

— Radio. Wireless connection over the air, usually through a wireless adapter connected to a computer via a USB port. The main advantage of this option can be called the actual absence of a wire; while the communication range is usually several metres, which gives freedom of movement and even allows you to use the keyboard as a "computer remote control". On the other hand, wireless models are much more expensive than wired ones, and their operation requires separate power supply from batteries or a rechargeable battery, the charge of which is limited — accordingly, the continuous operation time is limited. Separately, we note that this option is designed mainly for stationary PCs; if a wireless keyboard is needed for a laptop, it is better to pay attention to Bluetooth models (see below).

— Bluetooth. Another way to wir...elessly connect keyboards. Technically, Bluetooth is based on radio waves, but this technology has its own characteristics, so it is listed separately from the "normal" radio connection (see above). The main one of these features is that many models of modern electronics (almost all laptops and tablets, some PCs, etc.) are equipped with built-in Bluetooth modules, which allows you to connect such keyboards without using additional adapters. In addition, the range of such a connection is officially at least 10 m (in fact, of course, it depends on obstacles, interference, etc.). It is this option that will be optimal if you need a wireless keyboard for a Bluetooth-enabled device.

— Bluetooth / radio. Wireless keyboards that can connect both via Bluetooth and radio. See above for more details on each of these options. Also note here that such a keyboard is usually connected directly to a Bluetooth device (for example, a laptop), and if the computer does not support Bluetooth, you can connect a USB adapter to it and use a radio connection. Thus, the keyboard is as versatile as possible in connection. However, such versatility significantly affects the cost, and is required not so often; so this option is not widely used.

— Bluetooth / radio / wired. Keyboards that support all three connection methods described above. This is the most versatile option, giving the user the freedom to choose for different situations. For example, while playing a game or watching a movie, you can sit in a comfortable chair away from the screen by connecting the device wirelessly, and when typing or surfing the Internet, you can move to the table and use the wire, saving battery power. At the same time, such versatility is not often required and is expensive, so models with this type of connection are not popular either.

The length of the cable that the keyboard is equipped with for wired connection (see "Connection type").

When choosing this parameter, you should first of all take into account the distance from the device to the connection port: a cable that is too short may simply not reach the connector, and a cable that is too long may get confused at hand and create inconvenience. As for specific values, the reference length is 1.8 m. However, there are cables both shorter and longer.

The wireless connection range provided by the keyboard (see "Connection type").

Almost all modern wireless models function reliably at a distance of at least 2-3 meters. Therefore, you only need to pay attention to this parameter if the keyboard will be used farther from the computer. When evaluating the range, keep in mind that it is given for ideal conditions: no interference or obstacles, a fully charged battery, etc. In practice, the actual range might be somewhat shorter, so it's advisable to account for a margin when selecting a model. Nevertheless, the stated range can give a good indication of the practical capabilities of different models and help in comparing them.

Traditional keyboards are divided into three main varieties — full-size, compact and ultra-compact. The main difference between them is that full-size models have a Numpad — an additional block with numeric keys and arithmetic signs. Compact models, respectively, do not have a numpad, and in ultra-compact models, the arrow block is either completely absent or located under the Enter key in the form of very small keys.

And full-size, and compact, and ultra-compact keyboards can have different types of layouts. At the same time, the arrangement of letters and numbers above the letters in all types of layouts is the same, the differences are in the shape and position of additional keys (special characters like backslash, system control, modifiers like Shift and Alt, etc.). Here are the most popular options:

— ANSI. The "American" layout format, the distinguishing features of which are, in particular, the same width of both Shift keys, the same labeling and assignment of the Alt keys, the single-row Enter key and the backslash located above it (which is often made slightly longer than the standard key).

— ISO. "European" layout format. The Enter key occupies two rows, while at the top it is slightly longer than at the bottom; the left Shift is shorter than the right one, there is a...backslash next to it; next to the bottom of the Enter may be a second backslash or other special character key; the right Alt is designated as Alt Gr and is intended for entering additional characters in European languages.

— K.S. The "Korean" keyboard layout provides a double-row Enter, as in the ISO described above, however, in this case, the lower part of the Enter is made longer, and not the upper one. The backslash is above Enter, next to Backspace, and Backspace itself is the same length as standard keys (that is, noticeably shorter than in other layouts).

— JIS. Keyboards with a "Japanese" layout have a double-row Enter with an increased length of the upper half — like the ISO described above. However, in this case, the backslash is not located on the left side of the keyboard, but on the right, next to Enter (where an additional symbol key can be located in ISO). Additional character keys may be provided — next to Backspace (as in KS) and/or to the left of the right Shift. In addition, the right Alt can be formatted as Alt Gr.

In addition to compact and full-size, there are also non-traditional keyboard formats:

— Numpad. Separately made block of numeric keys. With the help of such a device, you can, in particular, turn a compact keyboard into a full-size one. Among other things, this combination can be useful for travel: packing a Numpad separately from the keyboard is easier than finding a place for a full-sized "board". Another option for using the Numpad is to connect to a cash register, terminal, etc. to work as a calculator keyboard or in a similar capacity.

— Keypad. A specialized device in the form of a small (approximately 15 – 20 keys) keyboard under one hand; usually, it is complemented by an arm rest, and often also by side buttons for the thumb. Such devices are especially convenient for games and are mainly used in them — certain game actions can be attached to the keypad buttons (including those that are usually implemented through the menu or a key combination on a standard keyboard). The keypad can both complement the main keyboard and serve as a completely separate game pad.

— Non-standard. Non-standard format keyboards that do not belong to any of the varieties described above. The specific design and use of such devices may vary. So, these can be game models in the form of the left half of a standard keyboard (this part is mainly used in games); ultra-compact models for tablets (see "In the direction"); keyboards for TVs, supplemented with special buttons and designed to be held in two hands in the manner of a gamepad, etc.

— Classic type. Keyboard with keys of the usual square and rectangular shape, with a small distance between them. Such keys usually expand downwards so that the gaps between them are as small as possible.

— Island type. Also known as "soaring" or chiclet. This is a keyboard in which each key is installed in a separate hole at a small distance from the others. Island models are more convenient than classical ones in that they are less likely to accidentally press the adjacent key. On the other hand, they are more difficult to clean: debris that has clogged into the gap between the key and the “board” itself is quite difficult to clean out, while contamination can create problems in operation.

On the practical side, the choice of a particular type of keys depends primarily on the personal preferences of the user.

The number of additional keys provided in the design of the keyboard.

Such keys do not belong to the standard layout and are intended for quick access to specific functions or individual applications — for example, to control the media player or open mail with one click. This function is convenient because commands from additional keys are usually recognized by the system regardless of what is on the screen — thanks to this, for example, you do not have to close the text editor to switch tracks in the player.

Note that in this case we are talking about individual keys that have a strictly defined purpose and corresponding markings. Programmable buttons, the Fn key (see below) and the functions of the main keys implemented through Fn are not taken into account in this paragraph.

The presence on the keyboard of the Fn key(short for function). It belongs to modifiers, similar to Shift or Ctrl: by itself it does not perform any action, but when pressed simultaneously with another key, it changes its original purpose. Fn is often found in compact keyboards (see "Format"), but can also be set in full-sized ones. The features it provides include quickly changing the screen brightness or sound volume directly from the keyboard, using the centre keys as a Numpad, launching individual applications, and so on. Specific features of using the Fn key depend on the keyboard model.

Volume control methodprovided in the keyboard (if such a possibility is provided at all).

— Through Fn. Adjustment using the Fn key (see above): increasing and decreasing the volume is carried out by simultaneously pressing Fn and one of the main keys of the keyboard (usually from the F1 — F12 row), The main advantage of this control is that it allows you not to overload the keyboard with additional controls — this, in turn, has a positive effect on the dimensions and cost. The disadvantage is the need to simultaneously press two keys, which is not always convenient.

— Additional keys. Control with additional keys specially designed for working with volume. A very convenient and practical option: additional keys are usually clearly labeled, while they take up less space and are cheaper than a wheel or a touch slider (see below).

— Wheel. Control by means of a mechanical wheel, the rotation of which up and down or left and right provides a change in volume. A fairly user-friendly option — visual, intuitive and accessible even blindly. At the same time, the wheel can take up quite a lot of space, and it significantly affects the cost of the keyboard.

— Touch slider. Management using a touch surface, the movement of a finger in one direction or another. The sensor takes up minimal space, looks neat...and generally fits well with the overall design of the keyboard, but it is not cheap. Therefore, this option is extremely rare, mainly in high-end gaming or multimedia keyboards.

The presence of an additional palm rest in the design of the keyboard. Such a stand is located in the lower (closest to the user) part of the device and is a kind of continuation of the “board”, providing additional support and increasing the comfort of use. However, comfort is largely a matter of personal preference, and not all users like stands; therefore, most often they are made removable.