Multiprocessing is a processing of programs using more than one processors. It is an ability of the system to support more than one processor and allocate task between them. In other words we can say it is a computer having multiple processing units which sharing main memory and peripherals to process multiple programs. Processes assigned dynamically to one or more computers that involve multiple working on the same program in parallel way. Execution of multiple concurrent processes in a system and each process running on the separate CPU is also multiprocessing at OS level. It also contrast with the term multitasking which is different from processing because it uses single processor and divide it into time slices to perform different task which is also known as time sharing. There are some of the components that form multiprocessors are CPUs IOPs connected to input and output devices, and memory unit that should be portioned into number of modules. Multiprocessor are classified as MIMD system i.e. multiple instruction multiple data.
Symmetric or tightly couple multiprocessor. SMP is also known as shared everything system but does not exceed more than 16 processors. The processor share memory and the I/O bus and data path. This is better than MPP for Online Transaction process which is OTP because in OTP many users access same database which is a simple set of transaction. Advantage of SMP it can dynamically balance workload from computers result of this, more user can serve faster.
Massively or tightly coupled multiprocessor. It support 200 or more processors can work on the same application having each processor of its own operating system and memory. The setup of MMP is very complicated which required thought that how to partition a common database and how assign work among processors. This MPP system is also known as shared nothing system.
Processing two Microsoft word file at the same time.