It is the first of a two-part adaptation of the 1986 novel of the same name by Stephen King, primarily covering the first chronological half of the book. It is the first film in the It film series as well as being the second adaptation following Tommy Lee Wallace's 1990 miniseries.

Yes, Stephen King has often drawn inspiration from real events and his own experiences when writing his books. For example, his novel "Misery" was inspired by a real-life fan encounter, and "The Shining" was influenced by his stay at The Stanley Hotel in Colorado.