Other forms: classics
The noun classic describes something that's very high quality, particularly if it has lasting value. The pristine Model T Ford that you keep in your garage is a classic, but the beat-up old clunker you drive every day is not.
You can also use the adjective classic to describe something that relates to ancient Greece or Rome. You can enjoy the classic Greek-style columns on the outside of your house but still appreciate the modern plumbing on the inside of it. Classic also means excellent, of recognized authority, or definitive. Classic literature, for example, includes that written by authors like Mark Twain and Jane Austen.