Disturbance - a wave is a repeating disturbance or vibration that transfers or moves energy from place to place.
Energy - In electromagnetic waves, energy is transferred through vibrations of electric and magnetic fields.
Vibration - it is a repeated back and forth or up and down motion.
Medium - it is a material through which waves can travel. It can be solid, liquid or gas.
Source - waves are created when a source of energy (force) causes a vibration.