kill command is used to kill or end process. It uses signal for process to act upon. There are list of signals like 9 is for SIGKILL which kills process forcefully, 5 for SIGTRAP etc.
kill [option] [..pid...]
[ -L ] :It list all the signals.
[ -s ] :It takes signal
killall command is used to process by name.
killall [options] [name]
[ -u ] : It kills process from that user only.
[ -r ] :It determines process name by regular expression.
[ -i ] :It ignore case sensitivity for process name.
[ -q ] :It makes killall process silent if no process is killed.