Whey protein is one of the two major groups of proteins found in milk. Only 20 percent of milk's protein is whey. The rest is casein, which is the protein that triggers most milk allergies. This is why whey protein would be a way for people with allergies to get dairy protein into their diets. It's typically sold in powder form, as either whey protein isolate or whey protein concentrate.
Shakeology only contains 16g of protein...split somewhere between whey and pea (if you are drinking regular shakeology). It is considered a wellness shake or meal replacement, not a protein shake.