When the OS at the explicit request of another process creates a process, this action is called process spawning.
To create a child process in a multitasking operating system. E.g. Unix's fork system call or one of the spawn() library routines provided by most MS-DOS, Novell NetWare and OS/2 C compilers - spawnl(), spawnle(), etc.
In Main Memory there may be residing many process. To avoid overflow Operating systems use different techniques to swap out pages of processes for Main Memory(Runny state) to Hard disk(Ready state in Ready Queue) and vice versa. this is called process swapping