2D animation has already existed since the end of the 18th century. So, 2D or two-dimensional when spelled out, is a very traditional animation method. However, 2D also focuses on creating characters, storyboards, and backgrounds. Therefore creativity as well as technological skills are both required.
2D can be made by hand or with a computer, but in both ways you can only see one angle at a time. For this reason 2D animation only displays characters height and width as for in 3D animation you also display their depth. When working with a computer you can use a special kind of software for 2D animation. Some examples are: Adobe After Effects, Adobe Flash Professional, Motion, Toon Boom, and Anime Studio.