The region is southeast of the Gulf of Mexico and the North American mainland, east of Central America, and north of South America. Situated largely on the Caribbean Plate, the region has more than 700 islands, islets, reefs, and cays.

The Caribbean region is home to a vast and diverse archipelago comprising more than 7,000 individual islands, islets, reefs, and cays. However, when people refer to the "Caribbean chain," they are often thinking of the major inhabited islands and sovereign nations. Geographically, these are divided into three main groups: the Greater Antilles, the Lesser Antilles, and the Lucayan Archipelago (which includes the Bahamas and the Turks and Caicos Islands). The Greater Antilles consists of the four largest islands: Cuba, Hispaniola (shared by Haiti and the Dominican Republic), Jamaica, and Puerto Rico. The Lesser Antilles is a long, curving chain of much smaller islands that stretches from the Virgin Islands in the north down to Grenada in the south, further divided into the Leeward and Windward Islands. There are 13 independent island nations in the Caribbean, such as Barbados, Saint Lucia, and Trinidad and Tobago, along with numerous overseas territories belonging to countries like the UK, France, the Netherlands, and the US. While the 7,000+ figure includes every tiny rock and sandy cay, only about 1% of these are permanently inhabited. This complex network of islands was formed by a mix of volcanic activity and coral growth, creating one of the most biodiverse and culturally rich maritime regions in the world.