Oceans And Seas Questions
A reef is a submerged ridge or platform made up of coral, rocks, or other organic materials found in the ocean. It can be found close to the surface or just below it.
An atoll, on the other hand, is a ring-shaped coral reef or a series of coral islands that encircle a lagoon. Atolls are formed when a volcanic island sinks or erodes over time, leaving behind a circular reef structure with a central lagoon.