five kinds of IPC methods

• Shared memory permits processes to communicate by simply reading and writing to a specified memory location.
• Mapped memory is similar to shared memory, except that it is associated with a file in the filesystem.
• Pipes permit sequential communication from one process to a related process.
• FIFOs are similar to pipes, except that unrelated processes can communicate because the pipe is given a name in the filesystem.
• Sockets support communication between unrelated processes even on different computers.