Is coral reef a plant or an animal?

A coral reef is made up of dead coral bodies, skeletons if you will. Coral is an animal. But a coral reef becomes a wonderful home for undersea plants and animals alike.

Coral reefs are aragonite structures produced by living organisms, found in marine waters containing few nutrients. In most reefs, the predominant organisms are stony corals, colonial cnidarians that secrete an exoskeleton of calcium carbonate. The accumulation of skeletal material, broken and piled up by wave action and bioeroders, produces a calcareous formation that supports the living corals and a great variety of other animal and plant life.