Minicomputers are computers that are somewhere in between a microcomputer and a mainframe computer. In times past, the minicomputer was typically a stand alone device that was ideal for use by small and mid-sized businesses who needed more power and memory than could be obtained with microcomputers, but did not have a need for the resources provided by mainframes. More recently, a minicomputer is thought of in terms of being a server that is part of a larger network.

In the early years of computer technology, a hierarchy of computer sizes and types was used to define the level of operation needed for different types of applications. The levels ranged from the embedded systems that functioned more or less automatically to parallel processing systems that was capable of supporting a huge network of interconnected computers and performing a wide array of tasks simultaneously. The minicomputer tended to be somewhat low on the hierarchical listing, in that the device was considered to be limited in ability.

The original structure for a minicomputer was a simple computer system that was equipped with essential programs and functions that would handle simple tasks, such as word processing. The minicomputer was equipped with terminals that made it possible to attach peripheral devices to the system, such as a printer. However, the minicomputer usually did not have hardware or software that allowed the device to be integrated into a larger network. However, if there was no need to use comprehensive applications or interact with other systems, the minicomputer was often sufficient.

Over time, the concept of a minicomputer has become somewhat obsolete. As technology has continued to evolve, many tasks that were once the exclusive province of the larger and more powerful mainframe computers has been assumed by the workstation computers of today. Still, the mainframe remains in existence, although the purpose and function is often associated with the role of a large server to support a network of workstations. In like manner, the minicomputer has morphed into a server that is ideal for smaller and more localized networks.