In ecological term, coral reef is an ecosystem in which the main
building block is individual stony coral animal
There are three types of coral reefs: fringing reefs, barrier reefs
and atolls
Fringing reefs
Fringing reefs are coral reefs closely encircle the edges of
continents.
When the continent sinks gradually and the living fringing corals
keep growing upward at a faster rate, a barrier reef and finally
an atoll reef will be formed.
Barrier reefs
Barrier reefs refer to those reefs scattered on the outside of
the continental margins with a lagoon separates the land and the
reef. The famous Great Barrier Reef in Australia stretches over
2,000 km and is the world's largest barrier reef.
Atoll reefs
Atoll reefs refer to ring-shaped coral reefs and the water enclosed
in the ring is a lagoon.
