Tennis Wars: Hit VS Push

What is better in tennis, hit or push? My coach (mom) says it is push. You shouldn't just whack the bard with the racket, even though you think it would go far, it wouldn't. But push is the same. That is why we bring the racket back and then push the ball forwards. We pull the racket back to gain strength when we push it. Then it will go much more farther. What do you think?