A reef-building coral formation that parallels the coast is called a fringing reef.
Fringing reefs grow directly adjacent to a shore or around an island, often with little or no lagoon between the reef and land. They are one of the principal geomorphic reef types found in tropical oceans, alongside barrier reefs, atolls, and patch reefs.
The Great Barrier Reef includes many different reef forms rather than being one uniform wall of coral. Its complex structure contains fringing reefs near islands and the mainland coast, platform reefs, ribbon reefs, patch reefs, and other formations. The term “Great Barrier Reef” therefore describes a vast interconnected reef province, not just a single barrier-shaped ridge.
A barrier reef generally lies farther offshore and is separated from the coast by a lagoon or other broad water space. An atoll surrounds a lagoon and usually develops around a subsiding volcanic island. These distinctions are based on position and shape, not on whether the corals are healthy or damaged.