anime - (from the French word for animation) While fans debate the boundaries of the term, "anime" generally refers to animation produced by Japanese animators for Japanese audiences. Some fans will argue that animation produced by Japanese animators for western audiences (such as some of the Transformers series) cannot be classified as anime. Others use the term to refer to animation, no matter where produced and by whom, that displays the visual conventions of Japanese animation. As anime has become more popular in the west, some western cartoon producers are adopting those conventions for their own cartoon series.
doujinshi - "Doujinshi" refers to manga that are produced by fans. As manga, they bridge the fan art and fan fiction categories in that the doujinshi creator is both writing and illustrating a story in the world of a particular manga. Some doujinshi creators have gone on to become manga creators in their own right, such as CLAMP, a group of Japanese women whose manga have inspired a number of anime series.
fan art - Fan art refers to drawings of anime characters made by fans.
fan fiction - Fan fiction refers to stories written by fans involving characters and situations from an existing story
manga - Manga is the term for Japanese comic books. Manga series are produced for a wide variety of audiences, from young children to adults. (Some manga for adults is pornographic.) Manga are becoming readily available through western distributors, including such bookstore chains at Waldenbooks, Barnes & Noble, and Borders.
shoujo - The Japanese word for young girl, "shoujo" is used to refer to manga and anime aimed at this market. Depending on the age range, the stories may be quite cute or romantic.
shounen - The Japanese word for young boy, "shounen" is used to refer to manga and anime aimed at this market. The storylines are more varied than shoujo storylines and often the thread connecting them is publication in a shounen-marketed periodical.