When the sun heats the air, it causes the air to become lighter and float upwards. When hot air floats upwards, cooler air rushes in to take its place. The rush of the cool air against the water creates ripples, which eventually turn into waves.
Just as wind is the source of cool, refreshing breezes that are felt on sunny days, it is also the source of the movement of waves. As wind moves up along the water, there is friction, which causes the water to ripple. The wind continues to rush forward, and it presses against the ripples. Pushing against the ripples constantly causes a snowball effect, which is what makes larger ripples that eventually turn into waves.
Waves work through the transfer of energy. Energy moves from the sun to the wind and finally to the water where the waves form.
There are three things that wind does to make waves larger. Winds that move faster increase the size of a wave. When wind stays in contact with a wave or moves against the wave, the wave can grow. A wave continues to move along the water in a circular motion until the energy forming the wave dissipates.