Audio books are recordings of books that are narrated by a professional reader. They are typically available as CDs or as digital downloads, and they are a great way to enjoy books if you don't have the time to read them. Audio books are often sold through retailers such as Amazon, Apple, and Audible, and they can also be found through library services. Audio books are great for commuters, students, and anyone who wants to relax and listen to a good book without having to read it.