The ocean is a highly random environment subject to the whims of nature. Waves are defined more technically as disturbances in the water surface due to the action of some external agent. These external agents are of the following types:
- Winds, with their interaction with the gravity forces, the most common ones, are also known as the gravity waves.
- Tidal waves caused by the action of tides (gravitational interaction between the earth, sun and the moon).
- Seismic activities like earthquakes or...
https://www.marineinsight.com/environment/swell-v-s-wave-whats-the-difference/