Animation is about creating the illusion of life. And you can't create it if you don't have one - Brad Bird (American cartoonist)
As a child, I wanted to be an animator.Back then, it was created in the traditional style, by hand, cell by cell, a painstakingly long process, but with a rewarding outcome. At the time, Disney was the leader of this art form. These days, with CAD (computer animated or aided design) practically anyone can create with some decent software (there are tons available) and practice.
I'm currently trying to teach myself CAD and have hit more than a few bumps in the road, the least of which is time.
There are generally 5 types of animation:
Traditional Animation. (2D, Cel, Hand Drawn) A transparent sheet, called a cel, short for celluloid on which images are drawn or painted used during the first half of the 20th century. Due to it's highly flammable and unstable nature it was replaced by acetate which has also been all but abandoned for other methods.
2D Animation (Vector-Based) created using bitmap and vector graphics created with computers and software programs like Adobe Photoshop, Flash and After Effects.
3D Animation (CGI, Computer Animation) used by animating objects as they would appear in a three-dimensional space and in the heart of games and virtual reality they can be rotated and moved like real objects.
Motion Graphics (Typography, Animated Logos) created with digital footage or animation which uses the illusion of motion and often combined with audio in multimedia projects. Most used in commercial utilzation of animation in film and interactive applications.
Here is a sample I created in blender.
Stop Motion. (Claymation, Cut-Outs) a technique used when objects are physically manipulated in small increments between photographed frames to that they appear to move on their own when played as a fast sequence. Clay figures (claymation), dolls, household items and even humans can be used in this technique. Stop motion can also be sequential drawings or cut outs (pixiliation)