Here's why:

* Repeating disturbance or vibration: Waves are characterized by their oscillatory nature, meaning they involve a repeating pattern of disturbance or vibration.

* Transfers energy from place to place: Waves carry energy, allowing them to transfer it from one point to another.

* Without transporting mass: The medium through which the wave travels (like water, air, or a string) oscillates, but the particles themselves don't travel long distances. They simply move back and forth around their equilibrium positions.

Examples of waves:

* Sound waves: Vibrations in air that travel to your ears, allowing you to hear.

* Light waves: Electromagnetic waves that allow us to see.

* Water waves: Disturbances on the surface of water.

* Seismic waves: Waves that travel through the Earth's crust, caused by earthquakes.