[One] definition of Fandom (Media Fandom is sometimes used) is the shared appreciation of your favorite books, movies, TV, comics, etc. This can be expressed either through talking with other fans at conventions or via the Internet, or phone, or by whatever means -- or not at all. You can of course be a fan in the privacy of your own home. Fandom takes a wide variety of forms, many of which are creative, like costuming, art and writing, or don't require much creativity at all, like buying a book.