How do I make sure an app is turned off ?

I was running an app recently and when I wanted to turn the app off I went to the Taskbar then right-clicked on the mouse but did not see 'turn off app' or 'close app' or words to that effect.
In Windows XP Home I'm pretty sure the wording was unequivocal, 'turn off app' or something like that but with Windows 10 the wording is somewhat ambiguous which is 'Close Window'.
Now, is that the same as 'close app' or 'turn off app' ?
So, by clicking 'close window' is the app also closing down or am I merely just closing the window but (inadvertently) leaving the app on ?

 

It depends on the "app". Some can be turned off that way but others cannot.

What is the name of "app", and what version?

 

Not sure if you can help me when I tell you it's qbittorrent.