Reefs and corals are actually two different things, although often mentioned together as coral reefs, the relationship between coral reefs and reefs is there, yet hard to describe.
A reef, in its essence, is a rock, defined as a rock near the water surface in rivers or oceans, not necessarily visible above the water.
However, the expert's definition states that even rocks on islands covered with soil and vegetation, which are not exposed above the sea surface, are also considered reefs, understood as any rock grown near the sea.
What we just talked about, corals, are actually a type of animal, that's right, they are animals not plants, corals are made up of millions of coral polyps' dead bodies, and a coral reef is essentially these bodies grown on the reef.
Most marine life, just like terrestrial organisms, needs a place to hide, a cave to protect themselves, which is why, generally speaking, there are many marine creatures near reefs and coral reefs.
