Описание тега process
A process is an instance of a computer program being executed. Many operating systems let multiple processes run concurrently. The operating system takes care of isolating processes one from another in order to provide data integrity and also provides means for interprocess communication (IPC).
Process contains the program code and its current activity. Depending on the operating system (OS), a process may be made up of multiple threads of execution that execute instructions concurrently.
A computer program is a passive collection of instructions; a process is the actual execution of those instructions. Several processes may be associated with the same program; for example, opening up several instances of the same program often means more than one process is being executed.
For security and reliability reasons most modern operating systems prevent direct communication between independent processes, providing strictly mediated and controlled inter-process communication functionality.