Editing UV polygons
Each object polygon has a UV polygon on the texture to control which part of the texture is mapped onto the object polygon. Because each object polygon has a UV polygon, the number of UV polygons equals the number of object polygons. If you delete an object polygon, its UV polygon is also deleted.
The UV polygon is otherwise independent and can be moved, scaled and rotated. In other words, no matter how you move, scale and rotate the UV polygon, the position, size and direction of the object polygon remains unchanged. All that changes is which part of the texture gets mapped to the object polygon.
For example, suppose a UV polygon is over a black part of the texture. As a result, the object polygon is black. Next you move the UV polygon to a red area of the texture. The object polygon itself is not moved, but turns red.
To display textures in the view panel, ensure that Disable Textures is disabled on the Display menu and choose a shading mode (i.e. Gouraud Shading or Quick Shading).
You can, if you wish, place UV polygons on top of one another. All UV polygons can occupy the same part of a texture, in which case each object polygon would receive the same part of the texture. Take a look at the following examples.