A hybrid computer is a computer system containing both analog and digital devices so that the properties or each can be used to the greatest advantage. For instance, a digital and an analog computer can be interconnected so that data can be transferred between them.

Large electronic hybrid computer systems with many hundreds of operational amplifiers were widely used from the early 1960s to the mid-1980s. They solved extremely complex and extensive sets of differential equations (mathematical models) such as six-degree-of freedom space flights, exothermal chemical reaction kinetics, control systems for food processing plants, and the human immunosuppressive system.

General-purpose hybrid computers are hybrid computers with the ability to use different applications or to be able to solve numerous kinds of problems. Many general purpose hybrid computers were once purpose systems, either part time hybrid computers in which the outcome were achieved in a relative speed or operation computers that utilize high speed.

Special-purpose hybrid computers contain fixed programs permitting few or no adjustments. They are generally built into physical systems where they serve typically as a subsystem simulator, function controller or results analyzer. For example, the pneumatic computer uses air bellows and flapper nozzles to generate accurate multiplication, division, squaring, or square-root functions of input signals, and encoding data as air pressures.