On user/role update – Is there a hook?

I’ve been source searching but my abilities aren’t that developed yet to pick up some things.

Just wondering if I am able to hook when a users meta has been updated, such as: when a users role is changed, I can get the username and do other things.

I have thought about adding a button that I can run after the role change, but would prefer just a function to hook into.

Thanks for the help,
Jay.