A process is an operating system abstraction representing an instance of a running computer program. A process is a key concept in operating systems.
It consists of data, a stack, register contents, and the state specific to the underlying Operating System (OS), such as parameters related to process, memory, and file management. A process can have one or more threads of control. Threads, also called lightweight processes, consist of their own stack and register contents, but share a processâ„¢s address space and some of the operating-system-specific state, such as signals. The task concept was introduced as a generalization of the process concept, whereby a process is decoupled into a task and a number of threads. A traditional process is represented by a task with one thread of control.While running overloaded machine aborts all process running to stabilize machine. Instead of aborting all process we can transfer active process on another machine.