Types of animation
2D animation
The term "2D" refers to animation that is created using two dimensional drawings.Classic hand drawn animation is the main example for this type. Think Disney features, like the recent Princess and the Frog.
You might also remember this from Sesame street - a piece by a wonderful animator
Computer assisted animation-Flash or AfterEffects cut-out animation is also considered 2D.
Many TV series are done in Flash these days.
3D animation-"3D" refers to Computer Generated Images (CGI) that create the illusion of three dimensional space with great accuracy.
Films like Toy Story and Up are 3D - CGI animation.
Computer special effects, also fall within this category. All the magical creatures and powerful spells in Harry Potter are done this way.We should bear in mind though, that in the end, 3D animation is also just a sequence of flat, two dimensional images projected on the screen.
Stereoscopic 3D, such as in Avatar, is the combination of two slightly different images that create the spatial effect, just like our own eyes do in the real world.
It is not a type of animation though, but rather a type of projection, like DVD, or a flip book.
Stop Motion Types of animation
Everything that is shot live, frame by frame, in front or under a camera is called Stop Motion or "Stop Frame" Animation.
Clay animations are usually the first thing that comes to mind in this category.
The different stop motion types obviously looks very three dimensional, the same way video looks three dimensional, but the term "3D" is reserved for computer