As in our busy life we required multitasking process and with the help of the Linux we can make the multi task processes.
Using the fork() system call(its not a function) we can create a newly process, which is known as child process having Pid set to Zero, and by using execl() system call we can make another process by passing the arguments from the main program and after calling execl() our main program(current process) is to be high jack by our newly process.