Comparison Logitech Keyboard K120 vs A4Tech KM-720

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 Num-block — an additional block with numeric keys and arithmetic signs. Compact models, respectively, do not have a num-block, 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, ther...e 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:

— Num-block. 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 Num-block separately from the keyboard is easier than finding a place for a full-sized "board". Another option for using the Num-block 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.

The distance that the key travels when pressed — from the initial position to touching the contacts and sending the "command". Indicated as high or low. Keyboards with low key travel(3 mm or less) are considered to be more comfortable for fast input (such as fast typing). However, the best option largely depends on the habits and preferences of a particular user.

Interface used in a wired keyboard (see "Connection type").

— USB. A standard universal connector for connecting peripherals, present in almost all modern computers — from desktop PCs to microcomputers. USB keyboards are the most versatile, so this option is the most common today. The main disadvantage of this option is that the USB slot occupied by the keyboard may be needed for another peripheral device; however, this problem is quite easily solved — for example, using a USB hub or purchasing a keyboard with its own hub (see below).

— PS/2. A specialized connector with a characteristic round shape used to connect keyboards and mice; in modern PCs, both two ports can be provided, for both, and one universal. Anyway, this connection method is convenient in that all USB ports remain free; this can be important when using numerous USB peripherals. At the same time, the PS/2 connector itself is rather large and poorly suited for laptops and other compact equipment, and therefore is found only in desktop PCs. And even in the latter case, it's ok to check the availability of PS/2 before buying a keyboard with such a plug.

— USB or PS/2. Usually, in this case, we mean USB keyboards equipped with an adapter for a PS/2 port. Features of both interfaces are described above; here we note that this option is the most versatile, it allows you to choose the connection method depending on th...e situation. In addition, it is convenient because there are relatively few PS/2 models, and it can be easier to find a suitable USB keyboard equipped with an adapter. The adapters themselves are inexpensive and do not really affect the price of the device; of course, they are sold separately, but the kit is often the preferred option.

— Corporate. Connection using a specific connector, which does not apply to the standard (described above) interfaces and is mainly used in the technique of a certain brand, at best, in some third-party devices. This option can be very convenient for tablet accessories (see "By Direction").

Protecting the keyboard from spilling liquid on it. Most waterproof keyboards do not have a full-fledged sealed case and are designed to remain operational in the event of accidental contact with a relatively small amount of liquid (up to 200 mL) — for example, in the classic case of spilling coffee on the keyboard.