pkill is command line utility to kill multiple processes at once.
Lets say we have multiple number of tomcat instances are running in a server, if we want to kill all tomcat instances we need to get all process id’s and kill them with kill command.
The advantage with pfkill is instead of using process id it uses process name. In Linux every process will have a name.
In our case for tomcat process name is Bootstrap.
Use pkill Bootstrap to kill all tomcat processes.
Similarly you can kill other process with pkill.