Shojo and Shonen are the two most known forms to us in the states, but there are several other types. Seinen is for adult males and Josei is for adult women. Manga is pretty popular here in Japan with all ages, and whenever I go to a ramen shop during lunch time, I’ve always seen guys in business suits eating their ramen with one hand while reading a manga in the other XD Much like you’d see a businessman here eating lunch and reading a book/novel here.
There is also a type for very young children called Kodomo (which is the word for child), and there is one that I LOVE! It’s called Chi’s Sweet Home, the episodes are about 3 minutes long each and are so funny and cute ^^ But I’m kinda getting into Anime with this one, cause I really haven’t had the chance to read any Chi. XD But it is soooooooo cute and happy and sweet!
Found image here.