Video (12:07): Example of using fork() for multi-process programming
The next three videos give 3 separate examples of using threads for multi-threaded programming. POSIX threads (pthreads) are available on most Unix systems. The 2011 C++ standard included built-in thread capability,and the 2011 C standard also included (optional) thread capability based in large part on the C++ standard.
Video (8:29): Example of using pthreads for multi-threaded programming
Video (10:40): Example of using C11 threads for multi-threaded programming
Video (7:03): Example of using C++ threads for multi-threaded programming