How to kill processes in Linux

This is a quick video showing 3 ways to kill processes in Linux.
1. Using the KDE System Monitor. This will work in any distro with a KDE desktop environment. If you are not using KDE it should be similar in your distro.
2. Using the terminal with the ps command. This will work in any distro
3. Using xkill. This should work in any desktop that uses x11.
Note: Before setting this up try [Ctrl]+[Meta]+[Esc] and [Ctrll] + [Alt] + [Esc] to make sure this isn't already configured. In the latest Kubuntu [Ctrl]+[Meta]+[Esc] is mapped to xkill by default.

[@shaheryarmuhammadali5843]

Nowadays internet browsers (chrome/firefox) spawn multiple processes after being started. Does using kill or xkill terminate the child processes as well or only the parent process? In Windows Task Manager and other equivalent Process Managers like Process Explorer and System Informer, we have the option to 'Terminate Tree' which will do the same.

[@nixnoob]

xkill will kill the main process and child processes for the window you click on. I forgot to mention killall which you use by typing killall and then the program name. Ex. killall chrome which will kill all processes for chrome.

[@k-universe0022]

Can you also make tutorials on Learning OS ?

[@nixnoob]

By learning OS are you referring to learning Linux itself as opposed to the KDE desktop? If so, I would be happy too.
Is there anything in particular that you would like to see? Most common commands, File structure, File permissions, Users and groups etc.