A simple comparison

After finding another blog to post my thoughts upon I find myself looking at the similarities and differences in or between American Comics, Cartoons, and other various animation to those in Japan, such as Manga or Anime. They both have simplistic abstractions of character design but what really makes them so different? As i sit and look at both forms of artwork I see that he Characters in America are more detailed or just as detailed as the background or landscape. With Anime Characters I am finding them to be more simplistic, or stand away from the landscape (at least for a majority of the comic or episode. There has to be more to it, everyone draws differently, this is a fact of life but what makes such a huge shift between cultures? Why would one be classified as manga and another an American comic? If you have any ideas, please share...