Multiple complete computers connected via a network, and operated as a single system.
In the computer world, a cluster can refer to two different things: 1) A ...
A parallel or distributed computing system made up of many discrete systems that form a single, unified computing resource. Clusters vary in their features, complexity, and the purposes for which they are best suited.
A set of independent computers combined into a unified system through system software and networking technologies.
The part of a computers memory that stores information about the components fitted to the computer - including the number and type of hard and floppy drives. This information is backed up on the motherboard with a small watch-type battery which provides power to the memory even when the computer is turned off, so the information will never be lost. If the battery goes flat the information will be lost and the computer will not be able to boot up.
Individual computers connected to act as one computer.
A cluster is a collection of workstations with software which allows the workstations to function as a single computer. Clusters of workstations can provide the same processing power as supercomputers at a fraction of the cost. The process of distributing tasks over the cluster is called load sharing.