Learning about Animation: UV Mapping

UV Mapping is a 3D modeling process in which a 2D image is projected to a 3D model's surface. A good analogy to understand UV mapping is cutting up a cardboard box. The box is a three-dimensional object which is similar to the mesh cube in the 3D program. If you were to cut the seam or the fold of the box, you would be able to lay the pieces flat on a flat surface. In 3D the u is considered the horizontal part of the texture and the v is the vertical ("Doc:2.4/Manual/Textures/Mapping/UV - Blenderwiki"). Therefore the image is essentially converted into two dimensions.

https://upload.wikimedia.org/wikipedia/commons/f/fe/Cube_Representative_UV_Unwrapping.png

The purpose of UV mapping is to make texturing easier, and to make the texture look good without stretching and pulling of the image. When a box is reassembled, a specific uv location is transferred to an (x, y, z) location on the three-dimensional box . This is what the 3D programs (Maya, Blender) does with a 2D image by wrapping it around a 3D object. When uv mapping your model it is good practice to assign a checkered board texture to your model to see if there is any warping, stretching or pinching. A good uv mapping should have squares that are relatively equal in size or kept at the same aspect ratio. This helps to preserve the quality of the texture you assign to the 3D model.