Skimmed v/s diluted milk
Diluting milk is what your doodhwala typically does… he adds water to the milk. Skimming milk is removing fat from the surface of the milk…something that you might be able to do if your doodhwala hasn’t diluted your milk a lot (for non-homogenized milk). Typically, various %s of skimming is done at a dairy to give you whole-skimmed or semi-skimmed milk.
Full cream, or whole milk, has the full milk fat content. For skimmed or semi-skimmed milk, all of the fat content is removed and then some (in the case of semi-skimmed milk) is returned. The best-selling variety of milk is semi-skimmed; in some countries full-cream (whole) milk is generally seen as less healthy and skimmed milk is often thought to lack taste.
Whole milk is about 4% fat. Semi skimmed milk is about 2% fat. Skimmed milk is about 1% fat. Fat in diluted milk depends on the % of dilution.