The Antilles are made up of the The Lesser Antilles, The Greater Antilles and The Leeward Antilles and together they form the West Indies. The Bahamas and The Turks & Caicos Islands, although part of the West Indies, are generally not included among the Antillean islands.
The Greater Antilles are the four largest islands in the northwestern portion of the Caribbean Sea and include Cuba, Hispaniola (Haiti and The Dominican Republic) Jamaica and Puerto Rico. They are called the Greater Antilles because they are so much bigger than the rest of the Caribbean islands. Straightforward enough, until we add in The Cayman Islands (Grand Cayman, Little Cayman and Cayman Brac)!
The Leeward Antilles is a chain of islands off the coast of Venezuela, which includes Aruba, Curacao, Bonaire, Isla la Tortuga and Isla la Margarita.
The Lesser Antilles are made up of both the Windward and the Leeward Islands. The Windward Island chain consists of St. Lucia, Grenada, St. Vincent and The Grenadines, Dominica and Martinique. The name dates back to the 1700's when English ships that were bound for Jamaica followed the trade-wind passage, these islands are exposed to the wind (windward) of the northeast trade winds (northeasterlies).
The Leeward Islands include the Virgin Islands, Guadeloupe, Montserrat, Antigua, Barbuda, St. Kitts, Nevis, Saba, Sint Eustatius, Saint Barthélemy, Anguilla, St. Martin/Sint Maarten, Redonda (Uninhabited), La Desire, Iles des Saintes and Marie-Galante. They're called the Leeward Islands because they're away from the wind (lee).
Barbados is located to the east of the Windward Islands. It is not, strictly speaking, a Windward, however it is most certainly in The Lesser Antilles and forms part of The West Indies. Like Trinidad, it is often included in a list of the Windwards but technically they both stand alone. Another island that causes further confusion is Dominica as it effectively creates the boundary line between the Windwards and The Leewards. In essence, it could really be in either but today is generally designated in the Windwards, although it was once a Leeward!