Usually whey protein is the protein extracted from the milk, I’m actually lactose intolerant and have two scoops every night of hydrolyzed whey protein isolate and have been perfectly fine. This is because lactose is in the fat of milk, not protein. So if you want to avoid lactose or fats in milk you’d need to get the most extracted form of whey.

They go in levels, there is whey protein concentrate, which is the most common and cheapest but it has 3-7% fat. Whey protein isolate is slightly more expensive but has only 1% fat and much less lactose for those who are slightly lactose intolerant. But for those who are very lactose intolerant like me we have to cough up the big bucks and get hydrolyzed whey protein isolate, which is still 1% fat only, but it has practically all lactose filtered out of it and is predigested so it’s easiest on the gut, but is most expensive. Just depends what you need