When I think of Classic Literature, I think of old books written by people like Jane Austen, Bram Stoker, Mary Shelley, etc. However, some people may consider books that everybody has heard of as Classics, like The Hunger Games, Twilight, and Harry Potter. So what is a Classic, really?
A Classic book is a book that had withstood the test of time. A book that people continue to enjoy years after it was published and it's author died. Their copyright has expired, and so they are printed by many different publishers.
These books generally contain a sort of appeal to where it is read by a diverse group of people. It will also contain some artistic quality, be it a writing style different from most other books, or an especially engaging plot.
Traditionally, Classic Novels were only fictional narratives. Recently, though, some graphic novels were shockingly referred to as 'Classics.'
This term is truly ambiguous. This set of 'rules' is only the generally accepted definition of a novel. There are no official requirements, but since books like Harry Potter and Twilight have not had a chance to withstand the test of time, I do not think they can truly be considered classics.