I love it when people use the phrase

Graphic Novel
Yeah it may sound pretentous but the distinction needs to be made, not because it means more quality (though usually does), comic books are more of serials, continuous and 1-issue with just dozens or so pages per thin papered issues series (magazines). Graphic novels is bit different, it used too broadly and generally to showcase difference of artistic value (subjective use), but in essene its a practical use for it.
Simple put unlike the above, is not an ungoing series, more one shot book, done in book material, usually experimental style, but also typical comic style too. But essentially its 1 shot story mainly, and usually as many pages as a typical book (instead of a brief issue like a comic).
Have both comic books and graphic novels, slightly different formats, to have V for Vendetta with its 300 or so pages, with an issue of Ultimate Avengers which is like 30 pages or so.