<P> Information appliances are computers specially designed to perform a specific "user - friendly" function--such as playing music, photography, or editing text . The term is most commonly applied to mobile devices, though there are also portable and desktop devices of this class . </P> <P> Embedded computers are computers that are a part of a machine or device . Embedded computers generally execute a program that is stored in non-volatile memory and is only intended to operate a specific machine or device . Embedded computers are very common . The majority are microcontroller s . Embedded computers are typically required to operate continuously without being reset or rebooted, and once employed in their task the software usually cannot be modified . An automobile may contain a number of embedded computers; however, a washing machine or DVD player would contain only one microcontroller . Embedded computers are chosen to meet the requirements of the specific application, and most are slower and cheaper than CPUs found in a personal computer . </P> <P> Public computer s are open for public uses, possibly as an Interactive kiosk . There are many places one can use them, such as cybercafes, schools and libraries . </P> <P> They are normally fire - walled and restricted to run only their pre-installed software . The operating system is difficult to change and / or resides on a file server . For example, "thin client" machines in educational establishments may be reset to their original state between classes . Public computers are not expected to keep an individual's data files . </P>

How can computers be classified on the basis of their size and performance