There are four different types of Computers as follow:
Supercomputers are the most powerful type of computer. These machines are special high-capacity computers used by very large organizations.
Mainframe computers occupy specially wired, air-conditioned rooms. Although not nearly as powerful as supercomputers, mainframe computers are capable of great processing speeds and data storage.
Minicomputers, also known as midrange computers, are refrigerator-sized machines. Medium-sized computers or departments of large companies typically use them for specific purposes.
Microcomputers are the least powerful,yet the most widely used and fastest-growing type of computer. There are six types of microcomputers: desktop, media center, notebook, and handheld computers.
Microcomputers are the most common type of computer.