Short answers, pulled from the story.
Gulliver's Travels was first published on the 28th of October 1726, priced at 8 shillings and 6 pence. It was written by Jonathan Swift, an Anglo-Irish writer and clergyman, and published anonymously by Benjamin Motte in two volumes.
Swift stated he wrote Gulliver's Travels "to vex the world rather than divert it". The novel was intended as a political satire targeting European governments, the Whig party, the Royal Society, and human nature generally, not as a children's adventure story.
Gulliver travels to Lilliput, a land of people less than 6 inches tall; to Brobdingnag, a land of giants where a farmer stands approximately 72 feet tall; to the flying island of Laputa and its associated territories; and finally to the land of the Houyhnhnms, where rational horses rule over savage humanoids called Yahoos.
The wars between Lilliput and Blefuscu mirror the conflict between England and France, while the high-heel and low-heel factions parody the Tories and Whigs. The character Flimnap is widely interpreted as an allusion to Sir Robert Walpole. The Grand Academy of Lagado satirises the Royal Society, and the Lindalino rebellion in Part III represents Dublin's resistance to British imposition of William Wood's debased copper currency.
The terms "big-endian" and "little-endian" in computer architecture are drawn from Gulliver's Travels, where Lilliputian religious sects divided over which end of a soft-boiled egg to crack. The terms describe two competing methods of arranging bytes in computer memory, chosen ironically because the technical debate mirrors Swift's satire of conflict over trivial differences.
Benjamin Motte altered and cut passages from Swift's original manuscript before publishing the 1726 edition, fearing legal prosecution. George Faulkner's 1735 Irish edition restored most of the original text using an annotated copy believed to have been prepared by Swift's friend Charles Ford. Swift added a letter to Faulkner's edition complaining that Motte had so changed the text that "I do hardly know mine own work", and this letter is now included in most standard editions.