Island Rings is a term used to describe two different types of islands. The first type is Leis, which are small, circular coral islands that are found in the Pacific Ocean. They are usually surrounded by a shallow lagoon and are made up of coral and sand. The second type is Atolls, which are also circular islands but are made up of a coral reef surrounding a central lagoon. They are typically found in the Indian Ocean and are often home to a variety of marine life.