A minicomputer is a type of computer that possesses most of the features and capabilities of a large computer but is smaller in physical size.

Mainframes are a type of computer that generally is known for their large size, amount of storage, processing power and high level of reliability. They are primarily used by large organizations for mission-critical applications requiring high volumes of data processing.

Minicomputer is a midsized multiprocessing and multi-user computer. It is also called a mid-range server. But mainframes are huge computers, most commonly occupying entire rooms or floor. It is highly costly.

Supercomputers are the fastest type of computer. Supercomputers are very expensive and are employed for specialized applications that require immense amounts of mathematical calculations. For example, weather forecasting requires a supercomputer. Other uses of supercomputers include animated graphics, fluid dynamic calculations, nuclear energy research, and petroleum exploration.