For further explanations,
Waves is the sea state (also called total sea) that you can observe in a given place. It is a mix of different waves :
Waves = Wind Waves + Swell 1 + Swell 2 + Swell 3
Wind waves (see other layers) is waves generated by the local wind
Swell 1 is the main swell generated by a remote wind. The swell travels great distances to where you observe it.
Swell 2 is a smaller swell generated by a remote wind in another place.
Swell 3 mostly is very small and often neglected.
The difference between Swell 1 , Swell 2 and 3 is their significant heights.

What is the interest of knowing these different types of waves?
For Surfers the best conditions are a strong Swell 1 with low Wind Waves and low Swell 2/3. With strong Wind Waves and strong Swell, waves are very disorganised especially if their directions are different ... "like in a washing machine".
For Sailors, Wind Waves at 90º of the Swell direction give a "cross sea" tougher than a sea with all kind of waves in the same direction