Good question.
I think it is an idiom - Jura confirm this please if you will <3
It means to be separate from, or to actively spend time away from.
A break, is what we say when we are in work, but we are having our sandwiches etc
I'm on my break from 12:00 to 12:30 so I'll speak to you then.
Break is also a physical thing, which means to take something which was perfect and damage it, a broken arn, a broken computer, but you can break habits too and break up with a girlfriend.
If you broke your boyfriend's nose he'd break up with you, but if he loved you very much he might think about it but ask for some time away from you, and you two would be on a break
Ok? :)
Craig