(1) A set of individual components, such as people, machines, or methods, that work together to perform a function.
(2) A computer and its associated devices and programs.
(3) A single node or a cluster of nodes acting as a single computing entity. A system in this sense may run multiple instances of the operating system. See also cluster node.
(4) A functional unit, consisting of one or more computers and associated software, that uses common storage for all or part of a program and also for all or part of the data necessary for the execution of the program. A system can be a stand-alone unit, or it can consist of multiple connected units.