The way I understand it if it's animated, even CGI animation, it's a cartoon. If it is animated in Japan, then it is anime. It's still a kind of cartoon of course but totally different in style and writing of story. I did a report on this in college but it's still hard to explain specifically. I personally don't like when someone says, "oh anime that's just means cartoons." Saying it like that just makes someone not familiar with anime think it's like something for kids, which is sorely not the case.
Many of the younger anime people I meet (I'm older than most of them) tell me if it's not drawn by Japanese in Japan, it's not technically anime. I tend to agree with them, which is why I hate when they put Marvel graphic novels in the manga section in the library. Manga being the same principal as having to be Japanese by Japanese.
That's just my thoughts on it.