I think it is the command I miss the most. Right now,there is a program not responding and I cannot close it. The kill command in Terminal is useless to me because I have no idea what "button 2" is. I have tried but I CANNOT find it. All I can do is restart, which takes soooo long and is a "pita". Is there something I can type into the Terminal like kill SURFSHARK, or whatever... ??
Excuse my typing, I am using a 2/3rds bluetooth keyboard that isnt English... meh!
I do not understand these two points in relation to each other.
Yes, you can kill a process with a terminal command by using kill plus the program name or its PID
If you are on Xorg (x11), you can use the xkill command which is very much like ctl+alt+del: I use it with the assigned keyboard shortcut ctl+alt+k
Try launching the System Monitor -> Processes, but I'm just not sure if you can right-click on a given process to shut it down from there. You can, however, note down the ID of the process that you want to shutdown and run a command in a terminal:
kill ID
Despite the name, this command asks politely to the process with the given ID to shut itself down. So, give a few seconds to see if responds.
Otherwise, you can go full Kill Bill on it... but before I tell you how to do that, you need to understand that this will destroy the process without giving it a chance to clean up after itself. This means that any configuration files that were modified (as VPN clients tend to do) will be left as they are. This can leave your computer in a bad state even after rebooting...
So, you might want to start troubleshooting first why the VPN client is not responding in the first place.
Easiest way to manage performance & apps of your PC on Linux, is to use Mission Center. Its very user friendly, and it works great.
If you click on the "APPS" tab, thats where you can kill a app/process.
Right click on the app/process, and click on force stop.
You can find "Mission Center" in the "Software Store."
Hope this solves your issue, and makes your computing life a pleasant one. 
Ctr_Alt_Esc launches XKill, which you can then use to close any open application. I only discovered this earlier this year, in another forum post, How to kill any process immediately. For me, it's generally Firefox that's causing the problem (too many tabs and/or some sites really chew up the RAM), and when the system runs out of RAM I can't open the task manager or anything else to kill it.
Apologies for not being more clear, I was tired, frustrated, just trying to relax a little before going to sleep.
I will read through all replies carefully tomorrow and edit this response. Thanks everyone!
