Juvenile/Whimsical: Very sweet, cute styles.
Some examples of these styles would include Dora the Explorer, Arthur the Aardvark, Winnie the Pooh and Fancy Nancy. This category and Cartoon/Humor can sometimes overlap. (Examples would be some of the Disney art or Olivia the Pig. This style of art can be cute and whimsical, yet sort of humorous.)
Cartoon/Humor: Humorous and funny.
Some examples of this style would include Looney Toons (Bugs Bunny, Daffy Duck, etc), Hanna Barbera (The Flintstones, Scooby-Doo etc.) or Spongebob Squarepants. Caricatures would fall under this category too.
Fantasy Style: This style would be more of a mythical-type style.
Examples would include superhero/comic books (Superman, Batman, etc.), Manga, Dungeons and Dragons, or even Harry Potter book cover art.
Science Fiction: Star Wars, X-Men, and Transformers.
Naturalistic: Reproducing a simple likeness or similar characteristics of people, objects or animals or actual historical events, etc. Closer to a more realistic rendition.