Whey protein typically comes in three major forms: concentrate, isolate, and hydrolysate. Most of the whey protein powders you find will contain mostly whey protein concentrate with some whey protein isolate mixed in. You'll also find a lot of pure whey protein concentrate, and some whey protein isolate. Comparing the two, whey protein isolate is more expensive than concentrate - because it's of higher quality(more pure), and have a higher biological value (BV). Whey protein isolate contains more protein with less fat and lactose per serving. Usually, isolate contains 90-98% protein while whey concentrate contains 70-85%.