They are most often used as a locking mechanism to prevent processes from accessing a particular resource while another process is performing operations on it. Semaphores are implemented as sets, though a set may have a single member. System V IPC Shared Memory Shared memory is a mapping of an area of memory into the address space of more than one process. This is the fastest form of IPC as processes do not subsequently need access to kernel services in order to share data. A network inter-process connection protocol based on Sun Microsystems' RPC standard.
Sockets allow local or network connection between processes.
Socket names are implemented within a domain. In the UNIX domain a socket is given a path name within the file system. Other processes may use that name to communicate. Event handles may optionally have names and are signalled using the SetEvent call. Anonymous Pipes Used primarily for communication between related processes.