Alexander Prohorenko says, IPC is one of the most important features of the UNIX systems. It allows two processes to communicate with each other. In this article we’ll work with two System V IPC functions, semaphores and shared memory. System V IPC originated in SVR2, but has implementations by numerous vendors. It’s also available in SVR4.
IPC is a complex concept. The term includes various mechanisms of data exchange between processes started on one system. IPC lets you avoid creating a huge application with a big set of the diversified functions in favor of using separate, small applications that can exchange data with each other. While this is more of a traditional Unix approach, using separate applications allows multiprocessor systems to execute applications in separate threads to reduce the time of performing specific tasks. Read more.