Scales the UVs of the selected faces to within the 0 to 1 range of the UV texture space.
Use the following options as required to Normalize the UV texture coordinates.
Turn this option on to scale the UVs uniformly along U and V.
Turn this option off (the default setting) to stretch the texture to fit by scaling U and V non-uniformly.
When you normalize texture coordinates, you scale the UVs of the selected faces. If Preserve Aspect Ratio is on, the scaling is guaranteed to be uniform on both the U and V axes. If turned off, the scaling will be different for the U and V axes.