What is the difference between an orphan and a zombie process?

A orphan is a child process whose parent process has finished. It is managed by the init process (or an equivalent in modern systems) and eventually terminates normally.

A zombie is a child process that has finished, but its parent process has not yet 'collected' its exit status (wait() or waitpid()). It consumes minimal resources but remains in the process table until the parent handles it or it terminates itself.