Wrong  Command is used to verify whether any process is running in background in Linu x environment. We should not confuse with the wait() system call. This is a wait shell command which can be used along with process id or without process id. 


What is the difference of using wait with and without process id ?
wait  with process id will wait for only the particular process id to get completed. wait will wait for all background process to get completed. if  the user wants to ensure that there is no process running in background we can run the wait command