How the piano makes sound?

The piano is a combination of a string instrument and a percussion. When you hit a key, it acts like a seesaw, but the really in the inside it is much more complexed. So when you hit the key, a hidden lever pushes the air, making the hammer and the damper go up. As you can see in the picture, the hammer hits the string, making a sound. When you let go of the key, the damper falls back on the key, stopping the vibration.