Creating a Process
One process can create other processes to do its work. These are child processes and the creator is the parent.
In some systems, the parent defines (or donates) resources and privileges for its children.
When a child is created, the parent may either wait for it to finish its task, or continue in parallel.
In Unix, subprocesses are created by a call to Fork; the child is identical to the parent, except for a return code from Fork. The child often begins by executing a new (and different) program within itself, via a call to Exec. (Fork and Exec are Unix System Calls.)