Whether it be to do your job, get your schoolwork done, clean your house, work on your creative passion, etc.
Bonus points if you’re someone without reasonable self-control so saying something like “I can only have a cookie after I do this/while I do this” doesn’t work for you and you’re just going to eat the cookie and not do it.
To mirror what others have said, there is a great quote I heard once, probably said first by some unknown person but later said by a billion others:
Personally, I heard it first from Josh Strife Hayes, but I’m sure he was not the first to have said that. :P