Computer are generally classified by speed, memory size and power consumption, though there is considerable overlap:
It is based on microprocessor chip as CPU. This is smallest category of Digital Computer. These computers include Personal computer Desktop computers, Notebook computers, Laptop computers, Tablet computers.
1. Personal computer – It is a small, relatively inexpensive computer designed for an individual user.
2. Desktop computers – A computer that is used for home application and small office work, is Desktop computer. In this type of computer, monitor is put on the top of computer and it is broad and low. While in tower computer, CPU cases are tall and narrow. In our general life we interact with Desktop Computer.
3. Notebook computers – It is a lightweight computer. A notebook size is also very less in comparison to Desktop Computer and Tower Computer. The display of notebook computer is different from Desktop Computer. Notebook computers price is very high in comparision with Desktop computer. It is easy to move from one place to another place. Notebook computer power is same as Desktop Computer. It is made of same configuration like 1 GB RAM, 1 TB HDD, DVD, etc…
4. Laptop computer -This type computer is little different from Notebook computers. Its configuration is near about same as Notebook Computer and it can be in the range of high configuration (4 GB RAM, 1 TB HDD, etc.) to low configuration (500 MB RAM, 500 GB HDD, etc.). Most of the times Laptop Computers are also called Notebook Computers.
5. Tablets – are smaller than laptop PCs, very lightweight, and easy to carry. But they lack the processing power of a laptop as well as a keyboard input. They rely instead on a stylus and touch screen.
A multi-user computer capable of supporting up to hundreds of users simultaneously. These computers are bigger in size and costlier than Microcomputers. Minicomputers are used in universities and big organisations.
3. Mainframe Computer
A mainframe computer is a very large computer capable of handling and processing very large amounts of data quickly. These are used by large institutions, such as government agencies and large corporations.
4. Supercomputers Or High Performance Computer(HPC)
A supercomputer is typically used for scientific and engineering applications that must handle very large databases. It is an extremely fast computer that can perform hundreds of millions of instructions per second. The speed of the supercomputer are measured by FLOPS (Floating point operations per second).