While whey concentrate is the cheapest and least refined type of whey protein powder, it does come with a couple of additional benefits.

If you are not lactose intolerant then you should not have trouble digesting whey concentrate.

Whey concentrate is the cheapest and least refined whey protein that is made from a milk byproduct of the cheese making process.

Unfortunately no, whey concentrate tends to retain quite high lactose levels and is unsuitable for those with lactose intolerance.