Coral reef is a marine ecosystem built by tiny animals called corals. These animals form hard structures that grow together over time. Coral reefs are often colorful and found in clear, shallow water. They provide space for many sea organisms to live.

Coral reefs are found in warm, tropical ocean waters around the world. They form over long periods of time. Coral reefs are home to many species of fish, invertebrates, and marine life. They are part of ocean ecosystems.