Archipelagos are groups of islands that are often found in oceans and seas. Some common synonyms for archipelagos are island chains, island groups, island clusters, and island ensembles. The term "island chains" is frequently used to describe lines or series of islands that stretch across a body of water. "Island groups" and "island clusters" both refer to sets of islands that are located close together and often share similar geography and ecology. "Island ensembles" is a descriptive term that encompasses the diverse formations of islands that can be found around the world. Whatever the term used, archipelagos have been formed through geological processes or through the actions of humans.