Often a cluster of workstations is viewed as either homogenous or heterogeneous. These terms are ambiguous, as they refer to not only the make of the workstation but also to the operating system being used on them. In contrast everything else is referred to as heterogeneous, i.e. a mixture of different makes of workstations. This includes connections between the computer and its disk and bulk storage system, connections to user terminals, graphics systems, and networks to other computer systems or devices. The system of logic and conductors that connects the processors in a parallel computer system.
Some examples are bus, mesh, hypercube and Omega networks.
The passing of data and information among the processors of a parallel computer during the execution of a parallel program. This term generally refers to an application sent to a batching system - a job finishes when the application has completed its run. The time taken to service a request or deliver a message which is independent of the size or nature of the operation. The latency of a message passing system is the minimum time to deliver a message, even one of zero length that does not have to leave the source processor. The latency of a file system is the time required to decode and execute a null operation.