A common misconception is that UV stands for ultraviolet. But, in the context of 3D, UV actually doesn't stand for anything. As we learned earlier in this book, we use the X, Y, and Z coordinates to describe where a model is in three-dimensional space, but we also have a U and a V coordinate to represent a model in two-dimensional space.
Why do we need to represent a model in two-dimensional space, you ask? Because that is how three-dimensional software attaches textures to a model. The two extra coordinates, U and V, are used to locate areas of a two-dimensional texture and map them onto a model's three-dimensional coordinates. However, before we can map a texture, we have to unwrap the model to create UVs.
A fun way to visualize this is with holiday candies:
Pretty cool, right? Who knew you could...