Greenland is a huge, frozen wasteland with almost no people on it. It sits in the North Atlantic Ocean. Bora Bora is a small tropical paradise in the South Pacific Ocean.
These two places are very different, but they have one thing in common. Both are islands.
An island is a piece of land with water all around it. Some islands are in rivers, lakes, and ponds. But most islands are in the oceans. Some islands, such as Madagascar off the east coast of Africa, are nations. Others are made up of two nations. For example, the island of Hispaniola in the Caribbean Sea is shared by Haiti and the Dominican Republic. Some islands are part of a larger nation. Sumatra is one of many islands that form the nation of Indonesia. Some islands are colonies or territories of other nations. The island of Puerto Rico is associated with the United States, but it is not a state.