# command to kill or terminate a process
kill <PID>
# To get the PID, display the running processes with the command below
ps ef
# There are several signals or options associated with the kill command
# To display them;
kill -l
# the default option is -TERM or -SIGTERM or -9
# We can run the kill command with other signals such as below;
kill -KILL <PID>
# we can use the serial number from `kill -l` of the signal to run the kill command
# for example, to forcefully kill a process
kill -KILL <PID>
# OR
kill -SIGKILL <PID>
# OR
kill -15 <PID>
# command to terminate all the processes of a particular program
killall <program name>