Starting off, a simple explanation is in order for this report. Manga is Japanese for comic, and anime is Japanese for animation. Both, when used outside of Japan, refer directly to Japanese animation and art. Often manga and anime are so closely related that they will have the same series in both versions. Fushigi Yuugi, for example, is a manga and an anime. They are almost interchangeable in some cases. If someone made mention of Petshop of Horrors, or even described part of the story line it wouldn't matter whether they meant the manga version or the anime version. However, when studied closer there are large differences between the two. If taken into context hundreds of differences could be unearthed. Therefore, art quality, quantity and styles need to be brought to light.
Normal animation runs at thirty frames per second, making anime abundant in art quantity. Every anime will have several million images in it, sometimes reaching billions depending on the length of the episode or show. Often frames will be sold as cels, a slang term for celluloid. Cels are created in batches to form complete sequences or actions in a movie. In contrary, manga have relatively few images. Instead of creating frames, manga are drawn in panels. Each page is laid out and separated, then each picture is drawn to create a storyboard. Even more space is used as rectangular and balloon shapes are reserved in order to place words into the story. So manga has much less space and immensely less pages than an anime. Though manga is comparable to American comics, but is usually left in black and white and drawn from top to bottom, right to left.
Manga have variably little space to convey images. However, often there is a front cover, back cover and inside cover to exhibit the characters, in full color, over the entire page. This is the source for almost all colors in manga. Without the covers most the looks and colors of most manga characters would be debatable. Pin-ups and specials also offer another chance to expose the manga in full color. Anime are always in full color. The colors are sharper, less detailed and not as soft as colors in a manga. People in anime are often less concentrated on, while the backgrounds can range from intensely beautiful to very plain. In long series single frames are concentrated on less, leaving the characters and their surroundings sometimes appearing strange or contorted in favor of creating a smooth scene.
Needless to say, manga cannot afford to have unsatisfactory images. Even though one poor frame out of thirty in an anime can pass for high quality, one poor panel in a manga can ruin a page. Manga depend on very few pictures to be able to show an entire story; every picture needs to be clean and pleasing to the eye. Having one sloppy picture can ruin a panel. A ruined panel is an entire page less appealing than the rest of the manga. It's essential in manga to keep the pictures as lovely as possible or else risk diminishing the value of the manga. In anime it's very common for several frames to appear odd individually. Instead of composing the cause and effect of an action as in manga, an anime must show the entire action, which occasionally looks odd in general. Basically, manga has more room to be aesthetically pleasing whereas anime has very little chance to do so.
In the manga Hamelin no Hiki, or Violinist of Hamelin, the characters are drawn with extreme personality. If the main character, Hameln, managed to loot a small child's house he would appear as a greedy demon, regardless of his normally lanky composure. Horns would decorate his head as he laughed heartlessly in rich attire, though Hameln actually always wears his hat with his caped bard outfit. Violinist of Hamelin is a comedy, and in this case the characters are represented in several ways other than what the characters truly looks like. The series Violinist of Hamelin has a completely different way of representing the characters. Hamelin never turns into a large greedy monster. Instead he's drawn as a very serious character. No longer is he beating on random people with his cello sized violin. Now he has a serious composure to maintain as he travels the land protecting his long time friend, Princess Flute. Many comedic aspects are lost in the anime, leaving only a few of the more outstanding pieces to sprinkle through.
Background is another important feature. Anime must have a background. Any anime that has a character pacing back and forth on a pure white screen will be discontinued quickly. Each scene requires a background to show the place of action, to emphasize a move the character is making, or even to reflect a character's thoughts. Manga can easily get away without a background. A panel showing only a picture of a character menacingly observing his foes will easily pass without having to add a potted plant next to him. Since manga must show what appears attractive, the motto "Less is more" applies. As demonstrated in the manga Wish, the demonic character Kouryuu need not throw the door open and stomped into the room to make his surprise entrance. All he needs to do is pose with an impish smirk etched on his face, with his name shouted in large lettering next to him. It can be automatically assumed he has swooped into the scene without having to draw everything around him.
There's a huge difference between anime and manga, despite the fact that most manga are developed into anime. The differences range from small to large: obvious to subtle. Nevertheless, they're there. No matter how hard a manga tries it can never be an anime, or the other way around. People prefer one to the other due to the differences, sometimes enjoying the action in the anime or the simple beauty in a manga. They journey hand in hand, influencing each other heavily and never quite attaining every characteristic the other has. Most would like it to stay as it is, as well. After all, if manga and anime became the same thing one couldn't delight in two versions of their favorite series.