Multiprogramming, Multicomputing, Multiprocessing and Multitasking

Multiprogramming: program may be any set of commands submitted for execution by a user or operator. In multiprogramming, concurrent running (sharing of the processor) is achieved when the operating system identifies the interruption of one program and gets chance to transfer process control to another program.

Multicomputing: A computer made up of several computers. The term generally refers to an architecture in which each processor has its own memory rather than multiple processors with a shared memory. Something similar to parallel computing.
Distributed computing deals with hardware and software systems containing more than one processing element or storage element, concurrent processes, or multiple programs, running under a loosely or tightly controlled regime.

Multitasking: The ability to execute more than one task at the same time, a task being a program. The terms multitasking and multiprocessing are often used interchangeably, although multiprocessing implies that more than one CPU is involved.

In multitasking, only one CPU is involved, but it switches from one program to another so quickly that it gives the appearance of executing all of the programs at the same time.

There are two basic types of multitasking: preemptive and cooperative. In preemptive multitasking, the operating system parcels out CPU time slices to each program. In cooperative multitasking, each program can control the CPU for as long as it needs it. If a program is not using the CPU, however, it can allow another program to use it temporarily

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Amit Ranjan
Java developer
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