Some different types of keyboards include QWERTY, AZERTY, QWERTZ and HCESAR keyboards, each of which vary with regard to the layout of keys. Other types of keyboards - which vary in terms of physical aspects like shape, the number of keys and the type of connector - include the ergonomic keyboard, the Apple Desktop Bus keyboard and the PS/2 keyboard.
QWERTY keyboards are thus named because the first six letters on the first row of the keyboard spell out "QWERTY." The same principle applies for QWERTZ, HCESAR and AZERTY, which is the French version of QWERTY. Another variant is the Dvorak keyboard, which places the most commonly typed letters in the middle row.
Ergonomic keyboards have a slightly different shape from that of standard keyboards. They're designed in such a manner that users can type while their hands are in a natural posture, therefore minimizing repetitive strain injuries. They're appropriate for people who spend a significant amount of time on the computer.
Apple Desktop Bus keyboards, or ADB keyboards, are keyboards that connect to Apple computers. Although designed to connect to ADB ports, they can be inserted into USB ports with a USB adapter. PS/2 keyboards feature a round jack with six pins and only connect to PS/2 ports. PS/2 keyboards are mostly used on IBM computers.