To present some contrast:

Windows doesn't have fork(). It has a real, fully mature thread and process model. In Windows NT, every process consists of a handle that is a "Process", which in turn points to a structure containing a list of "Threads". A process is done when its main thread exits or all threads exit, whichever is defined by the main process. Fork/Exec is replaced with CreateProcess (or ShellExecute, your choice).

For a very zen-like example of the fork/exec and pipe management that you'd do on a POSIX system done in Windows, the [MSDN Docs](https://docs.microsoft.com/en-us/windows/win32/procthread/cr...) are quite informative.