Another way of classifying a computer system is based upon its size and capabilities:

1. Microcomputers: Microcomputers are systems based on the use of microprocessors. A Microcomputer is a programable Large Scale Integrated circuit chip containing all the elements required to process binary encoded data. In other words, a microcomputer performs all arithmetic and logical functions of a computer. The microcomputer CPU differs from the conventional CPU and uses one or more silicon chips.
2. Minicomputers: In Minicomputers the speed is of the order of 0.5 to 1.5 Million Instructions Per Second (MIPS). Generally, Minicomputers have the word size of 32 bits or more.
3. Super-Minicomputers: Super-minis are faster than the minicomputers. These are generally 32 bit word length computers. The speed of the CPU is more than one Million Instructions Per Second. These machines support fast peripherals and have excellent time sharing operating systems.
4. Main Frame Computers: These are machines with word lengths of 32 bits and above. The speed of the CPU is about 10 Million Instructions Per Second. These computers support a large main memory. In time sharing mode, these machines can support hundreds of terminals.
5. Super Computers: Super Computers are the fastest computers and can be used to solve a wide range of large-scale problems which require extensive numeric computations. For example: Complex molecular structural analysis, weather prediction, etc. The speeds of the CPU are of the order of 100 million instructions per second (MIPS). These machines have word length of 64 bits and above.