What is the difference in whey permeate and whey powder?

Whey is the watery byproduct of cheese manufacturing which contains protein, lactose and other solids. As whey is further processed to achieve higher protein levels (i.e., whey protein concentrate and whey protein isolate). whey permeate is the byproduct. Whey permeate, also known as deproteinized whey or dairy product solids, is composed largely of lactose (approximately 80%), a natural sugar found in bovine milk.