(system cmd)When I don’t want to explicitly capture the output and return the control to perl script. (exec cmd) When I want to capture the output and don want to return back to the perl script

(exec cmd)When I don’t want to explicitly capture the output and return the control to perl script. (system cmd) When I want to capture the output and don want to return back to the perl script

(system cmd)When I want to execute system commands only (exec cmd) When I want to execute non system commands only

(exec cmd)When I want to execute system commands only (system cmd) When I want to execute non system commands only