It is helpful to create processes from a running process. For example, Apache (the web server) can create a new process to handle a new connection every time a client connects to the server. Furthermore, a Linux system starts with a single process initially, a mechanism must be provided to create all the processes of a normal running Linux system.
Even the use of the ampersand symbol in a CLI translates to a system call to create new processes. This section explores how this is done in a program.