hi, This 2D animation is NOT DONE by me, this just a video for u guys to
enjoy, Its know as the Animator vs. Animation 2. This is the Ver.2 of Animator vs. Animation. This guy is really good . The 2d effects he gave is soo real feel like. To know how is 2d animation done you can search this blog .
i really love the way he has done this 

3D animation

3D computer graphics 
are graphics that use a three-dimensional (3d animation) representation of geometric data, that is stored in the computer for the purposes of performing calculations and rendering 2D images. Such images may be stored for viewing later or displayed in real-time.

Despite these differences, 3D computer graphics rely on many of the same algorithms, as 2D (flash) computer vector graphics in the wire-frame model and 2D computer raster graphics in the final rendered display. 

3D computer graphics  (3d animation) are often referred to as 3D models. Apart from the rendered graphic, the model is contained within the graphical data file. . A 3D model is the mathematical representation of any three-dimensional object. A model is not technically a graphic until it is displayed. 

This is all about 3D animation

What is animation?

Animation is rapid display of sequence of images. The word animation has many meanings .To me animation is like being GOD, the computer is my earth and i can do anything build,create, brake, kill, bring life back, make own characters and soooo ON .In animation we got movies,short films, ads, games and a lot more.