audio book: (noun) a recording, as on compact disc or cassette tape, of a reading of a book by the author or by an actor(1) …the kind you may already check out from the library all the time. download: (verb) to transfer from a distant to a nearby computer(2) …such as the picture that someone sends you in an e-mail. downloadable audio book: (a very handy noun) the same exact recording of a book that you used to check out, but in the form of a computer file. That one file can contain every word, for instance, of a narrator reading Moby Dick out loud, that may have taken up 18 CDs. The file may be designed to play with one or another specific kind of program or equipment. It is intended to be transferred over the Internet to your own computer. You can listen to it on that computer with speakers or headphones, or you can transfer it to a Portable Listening Device, many of which can be set up to play through your car radio, or to take out walking, on a bus or train, etc. Some great things about it are that you don’t have to go anywhere to get it, and you don’t have to juggle a bunch of CD’s to listen to it—just press a button! (1) Webster's New World College Dictionary 2005 (2) Random House Dictionary 2009