Anime 101
If you do a search on 'what is anime' or 'anime introduction' using a web search engine, you'll find tons of links and descriptions. What I am going to do here is to sum them up. So, what is anime? Anime is the most common word used by fans to refer to Japanese Animation.Is anime the same as cartoon? Technically yes, however for anime fans, anime is not cartoon. See the definition above, anime refers to Japanese animation. So, the rule of thumb is as simple as: if it's not originated from Japan then it's not an anime (while the contrary is not true).
People usually think that anime is the animated version of japanese comic (manga). While in most cases this is true, however, not all anime is based on manga. For example, some anime are based on video games like Sakura Taisen and Tales of Eternia.
The Character Designs
In anime, faces are very streamlined, but are used to convey the wide range of human emotions. The designs are so simplified that the smallest curve can change the entire character's expression. Characters often have multiple styles of faces, such as the normal face, the serious face, and the ultra cartoony or super deformed face, all used for the same characters at various times depending on what the situation calls for.
Most important are the big glossy eyes, said to be part of the legacy of Disney, who had a big influence on pioneering Japanese animators, but are also used because of the high level of emotion that having large eyes affords.
Hair is another widely recognized feature of anime characters. Not only do characters often have outrageously huge hair styles, but anime hair comes in all various colors not naturally found on people. Used primarily to help distinguish character from character, the colors often times suggest something about personality traits. Hair is usually given the 3 shade treatment of highlight, regular color, and shadow and tends to be drawn very angularly.
Source: AnimeNfo.com