In computing, inter-process communication (IPC) is a set of methods for the exchange of data among multiple threads in one or more processes. Processes may be running on one or more computers connected by a network. IPC methods are divided into methods for message passing, synchronization, shared memory, and remote procedure calls (RPC). The method of IPC used may vary based on the bandwidth and latency of communication between the threads, and the type of data being communicated.
There are several reasons for providing an environment that allows process cooperation:
A system message sent from one process to another, not usually used to store information but instead give commands.
Most operating systems; some systems, such as Win NT subsystem, implement signals in only the C run-time library and provide no support for their use as an IPC method. But other subsystems like the POSIX subsystem provided by default until windows 2000. Then available with interix in XP/2003 then with « windows services for UNIX » (SFU).