The region consists of the Antilles, divided into the larger Greater Antilles which bound the sea on the north, the Lesser Antilles on the south and east (including the Leeward Antilles), the Bahamas, and the Turks and Caicos Islands or the Lucayan Archipelago, which are in fact in the Atlantic Ocean north of Cuba, not in the Caribbean Sea.

Some islands in the region have relatively flat terrain of non-volcanic origin. These islands include Aruba (possessing only minor volcanic features), Barbados, Bonaire, the Cayman Islands, Saint Croix, The Bahamas or Antigua. Others possess rugged towering mountain-ranges like the islands of Cuba, Hispaniola, Puerto Rico, Jamaica, Dominica, Montserrat, Saba, Saint Kitts, Saint Lucia, Saint Thomas, Saint John, Tortola, Grenada, Saint Vincent, Guadeloupe, Martinique, and Trinidad & Tobago. The climate of the region is tropical but rainfall varies with elevation, size and water currents (cool upwellings keep the ABC islands arid). Warm, moist tradewinds blow consistently from the east creating rainforest/semidesert divisions on mountainous islands. Occasional northwesterlies affect the northern islands in the winter. The region enjoys year-round sunshine, divided into 'dry' and 'wet' seasons, with the last six months of the year being wetter than the first half. The waters of the Caribbean Sea host large, migratory schools of fish, turtles, and coral reef formations.

Hurricanes, which at times batter the region, usually strike northwards of Grenada, and to the west of Barbados. The principal hurricane belt arcs to northwest of the island of Barbados in the Eastern Caribbean.