It's nice to get a pat on the back from the boss. "To get a pat (pat) on the back"
from someone means to receive praise from another person, or to have another
person say nice things about something you've done. When someone thanks
you for what you did, especially at work, you are getting a pat on the back. This
is an expression that doesn't mean the person actually touches your back; "to
pat" something means to touch it, usually lightly. You can literally - actually - go
up to someone and pat them on the back; that's a way of congratulating or
thanking them, but the expression is just used to mean you are getting praise,
you are getting appreciation.