Utopia is the name of a book. Thomas More wrote it in 1516. He wrote it in Latin. Its original title is De Optimo Republicae Statu deque Nova Insula Utopia. This is usually translated to On the Best State of a Republic and on the New Island of Utopia.
The book is about an island off the coast of South America with an imagined society. In the book, a visitor to this island tells about his trip there. According to him, Utopia has a system of laws that is perfect. Society there is also perfect. The political system is so good that nothing better can be thought out. Today, the word utopia is used to refer to a society that everyone wants to live in with perfect laws, but which is often hard to make.