Ireland is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially named Ireland – a sovereign state covering five-sixths of the island) and Northern Ireland (part of the United Kingdom – covering the remaining sixth). It is separated from Great Britain to its east by the North Channel, the Irish Sea, and St George's Channel. Ireland is the second-largest island of the British Isles, the third-largest in Europe, and the twentieth-largest in the world. As of 2022, the population of the entire island is just over 7 million, with 5.1 million in the Republic of Ireland and 1.9 million in Northern Ireland, ranking it the second-most populous island in Europe after Great Britain.
The geography of Ireland comprises relatively low-lying mountains surrounding a central plain, with several navigable rivers extending inland. Much of Ireland was woodland until the end of the Middle Ages. Today, woodland makes up about 10% of the island, compared with a European average of over 33%, with most of it being non-native conifer plantations. Its lush vegetation is a product of its mild climate, which is influenced by the Atlantic Ocean and thus very moderate, and winters are milder than expected for such a northerly area, although summers are cooler than those in continental Europe. Rainfall and cloud cover are abundant.