Manga is term that describes comic books and graphic novels, either originally produced and published in Japan or imitating the art style. Unlike American graphic novels—which are read top-to-bottom, left-to-right and are usually illustrated in full color—manga is typically printed in black-and-white (except for the cover art) and read top-to-bottom, right-to-left. Many manga stories are long-running series that span multiple volumes. It is important to start at the beginning and read the volumes in order.
Anime: Japanese-style animation (think Dragon Ball, Yu-Gi-Oh, or Sailor Moon). If a manga is popular enough, it may be adapted into an anime.
Manhwa: Comics and graphic novels originally produced and published in Korea.
Mecha: Manga featuring advanced techology, such as robots, cyborgs, androids, and space stations.
Kodomomuke: Manga that is geared toward children. These manga tend to be cute and fun. Pokémon is probably the best example of this.
Shonen: Manga that targets the tween/teen boys demographic. Common themes are action, adventure, friendship, and coming of age. Some examples of shonen are: Fullmetal Alchemist: Brotherhood; Dragon Ball Z; Yu-Gi-Oh; and My Hero Academia.
Shojo: Manga that targets the tween/teen girls demographic. Common themes are romance, drama, and coming of age. Some popular examples are Ouran High School Host Club; Sailor Moon; and Fruits Basket.
Seinen: Manga that targets adult men (ages 18+). Common themes are action, violence, sex, and adult themes. Some examples of seinen manga are One-Punch Man; Berserk; and JoJo's Bizarre Adventure.
Josei: Manga that targets adult women (ages 18+). Common themes are romance, sex, and drama. Examples of josei include Wotakoi: Love is Hard for Otaku; Honey and Clover; and The Delinquent Housewife.