Most pasta is made from semolina flour. Whole wheat pasta is made from whole wheat flour, or sometimes a mixture of whole wheat plus other flours are grains. Whole wheat pasta has more "texture" and can be rather bland and dry, even crumbly textured, depending on the brand.
This alternative pasta is higher in fiber and because of that has a lower-glycemic index which simply means it will raise your blood sugar more slowly and will be less prone to cause weight gain.
A single 2oz (dry) serving provides between 4 to 6 grams of fiber, depending on the brand.
See recipe suggestions for the best way to serve whole wheat pasta.