The main purpose of this tool is to quickly and easily set the object axis of a polygonal (not parametric!) object. Furthermore, the complete object (even parametric) can be moved to a defined position, including its axis.
Introduction to the concept of UV mapping a model. UV mapping is assigning new axis points to the object in order to tell the program how texture will adhere and react to the 3D model once they are placed and rendered.
Dustin talks to about how to select various elements within the UV editor and how to find them in your viewport model. This will help you understand how the UV editor interacts with the overall model and what type of preparations you need to make in order for textures to be overlaid later.
The way you overlay your materials onto any model/object is critical to realism. The UV checker will allow you to look at the skin of an object more closely and allow you to align things properly.
