Model of computer

ON THE BASIS OF MODEL
1. XT Computer
XT stands for extended or extra Technology. It is the old text based system with no GVI (Graphic User Interface). It supports only commands given in the form of text. So it is called CLI (Command Line Interface). Input and Output device was not so flexible and is slower than present device. Processor Like Intel 8080, 8086, 8088, etc. used this technology.

2. AT Computer
AT stands for Advanced Technology. AT computer is fast and run GUI based and CLI based on Operating System. Input and output are interactive flexible and faster. Processor like Intel, 80286, 80386, 80486, Pentium I, II used AT.

3. PS/2 Computer
PS/2 stands for Personal Computer System 2. It is a upgraded version of AT Computer with increased speed and performance. It is used in Laptop Computer having rechargeable and battery operated system along with faster and flexible input, Output device.