In shallow water, the wavelength of a wave is shorter than the water depth, while in deep water the wavelength is longer than the water depth. This means that shallow water waves are more affected by the bottom of the body of water, while deep water waves are not.
In shallow water, waves move by propagating horizontally, with the bottom of the wave touching the bottom of the body of water. As they move towards the shore, the wave height increases and the wavelength decreases, causing the wave to become steeper.
In shallow water, the speed of a wave is directly proportional to the square root of the water depth. This means that as the water depth decreases, the wave speed decreases as well.
Waves break in shallow water when the water depth becomes less than 1/7 of the wavelength. This causes the wave to become too steep and unstable, resulting in it breaking and dissipating its energy.
Shallow water waves interact with the bottom of the body of water through refraction, diffraction, and shoaling. Refraction causes the wave to bend towards the shore, diffraction causes the wave to spread out as it passes through a narrow opening, and shoaling causes the wave to increase in height as it approaches the shore due to the decrease in water depth.