What is the title of book about travels to countriesliliputs and giants?

The title of the book you are referring to is "Gulliver's Travels". It is a classic satirical novel by Anglo-Irish writer Jonathan Swift, first published in 1726. The book is divided into four parts, each describing the adventures of Lemuel Gulliver, a ship's surgeon, in different fantastical lands.

Part I of Gulliver's Travels takes place in the land of Lilliput, where Gulliver finds himself among a race of tiny people, only six inches tall. Part II describes his travels to Brobdingnag, where he is the opposite of Lilliputian, towering over the giant inhabitants of the land.

Part III takes Gulliver to the flying island of Laputa, where he encounters a society of scientists and philosophers, and eventually to the land of the Houyhnhnms, where he learns about a society of intelligent horses that treat humans as animals. Part IV of the book describes Gulliver's final voyage to the land of the Yahoos, a race of filthy, human-like creatures, and his subsequent return to England.

Throughout Gulliver's Travels, Swift uses satire and allegory to criticize the political, social, and intellectual climate of his time, making it a timeless and influential work of literature.