Difference between Cay and Island

Cay

Part of speech: noun

Definition: A small, low island largely made of sand or coral.

Island

Part of speech: noun

Definition: An area of land totally surrounded by water.An entity surrounded by other entities that are very different from itself.A superstructure on a large ship's deck

Part of speech: verb

Definition: To make into an islandTo set, dot (as if) with islandsTo isolate