Sea level is a term used to refer to the average height of the ocean's surface. It is also called the "mean sea level" and is used as a reference point for measuring elevations and water depths. Synonyms for sea level include "ocean level," "tidal level," "water level," and "coastal level." Other terms sometimes used to describe sea level include "mean high water" (MHW), which is the average height of the highest tide each day, and "mean low water" (MLW), which is the average height of the lowest tide. The term "mean sea level" can also be shortened to simply "MSL." No matter which term is used, sea level plays a crucial role in the natural world and impacts everything from coastal habitats to global climate patterns.