a sound is like a vibration that travel through the air ,or another medium and can be heard when they Reach's a person or animal' s ear........ the definition of vibration is like movement back and forth,or an emotion sensed by another person. a Sound waves is a way of compression and rarefaction by which sounds is propagated in an elastic medium such as air...... a Frequency is like the rate at which something occurs or it's repeated over a particular period of time or in a given sample.........