Desktop computer keyboards include alphabetic characters and numerals (and usually additionally a numeric keypad), typographical symbols and punctuation marks, one or more currency symbols and other special characters, diacritics and a variety of function keys. The repertoire of glyphs engraved on the keys of a keyboard accords with national conventions and language needs. Computer keyboards are similar to electric-typewriter keyboards but contain additional keys, such as the command key or Windows keys.
Laptop-size
Keyboards on laptops and notebook computers usually have a shorter travel distance for the keystroke, shorter over travel distance, and a reduced set of keys. They may not have a numeric keypad, and the function keys may be placed in locations that differ from their placement on a standard, full-sized keyboard. The switch mechanism for a laptop keyboard is more likely to be a scissor switch than a rubber dome; this is opposite the trend for full-size keyboards.
Flexible keyboards
Flexible keyboards are a junction between normal type and laptop type keyboards: normal from the full arrangement of keys, and laptop from the short key distance. Additionally, the flexibility allows the user to fold/roll the keyboard for better storage and transfer. However, for typing the keyboard must be resting on a hard surface. The vast majority[10] of flexible keyboards in the market are made from silicone; this material makes them water- and dust-proof. This is useful in hospitals,[11] where keyboards are subjected to frequent washing, and other dirty or must-be-clean environments.
Handheld
Handheld ergonomic keyboards[12][13] are designed to be held like a game controller, and can be used as such, instead of laid out flat on top of a table surface.
Typically handheld keyboards hold all the alphanumeric keys and symbols that a standard keyboard would have, yet only be accessed by pressing two sets of keys at once; one acting as a function key similar to a 'Shift' key that would allow for capital letters on a standard keyboard.[14] Handheld keyboards allow the user the ability to move around a room or to lean back on a chair while also being able to type in front or away from the computer.[15] Some variations of handheld ergonomic keyboards also include a trackball mouse that allow mouse movement and typing included in one handheld device.[16]