As a mathematician myself I'm inclined to say "everything's applied math", but it's really not the case. Physics studies and seeks after the basic laws that govern the universe. Physicists find mathematics very useful in these pursuits. But ultimately physics studies the universe and employs mathematics thusly. In theory, physicists could use other tools than math if those other tools were as useful or (preferably) more useful. I like to think of mathematics as the study of logical systems. That's how you can have mathematicians that specialize in biology, physics, music, and so on.