Different keyboards may have different keys or keys laid out in different ways, this is the subject of keyboard layout. In English speaking countries, the QWERTY layout is nearly universal. In countries speaking other Latin alphabet languages, small variations on QWERTY can be found; the Brazilian Portuguese and Spanish keyboard layouts, for example, while having enough differences to disrupt a QWERTY typist's fluency, have many more keys in common with QWERTY than not.
Other types of keyboards have been proposed for small portable equipment where QWERTY is too large. One way to reduce the number of keys is to use chording, i.e. pressing several keys simultaneously. As an example, the GKOS keyboard has been designed for small wireless devices.
See also: Keyboard technology, Chinese input methods for computer, SysRq, scroll lock, break key, RSI.