The Attack on Titan manga is a relatively short book that can be completed in about one or two hours. Its about a race of people who have ran away and hid away is large walls that protect them from the monstrous titans. The only thing they want in life is to kill people for fun. The one I read was only one of many book in a series that is still ongoing.
The Attack on Titan animated series is currently very short with only one season of 25 episodes. It takes on a very interesting art style that consists of mostly 3D animation which is usually saved for movies and specials. It is a animated adaptation of the hit manga attack on titan.(obviously)
Surprisingly, both the manga and TV. series are extremely similar. The TV. series is a movie adaptation of the manga, and being that the manga is not very long and does not use much imagery because all the pictures that depict whats going on. Even the Titans and characters have the exact same look that they have in the book. Down to which ones appear where. The only few thing I could find that were different. Which were that there are a few censorship of curse word and they toned down the blood and gore(persuasively because it was going to be aired on television) and finial, at the end, there was a different charterer that held the main character's injured body. but besides that, those are the only major changes I could find while reading the manga for the first time.
In all honestly, it very hard do deiced which is better between the to. On one hand you have the uncensored writing and beautiful had drawn artwork. But on the other hand, its more enjoyable to sit down and just watch the wonderful 3D animation and hear the music, voice acting, and special effect to add to the mood and create a more dramatic scenarios. All and all I would have to say that the TV. series is better because it is a more polished experience(meaning the mood it creates) with extremely high quality animation.