Concentrate vs isolate vs hydrolysate

All three are whey protein; they differ in how far they're filtered:

• Concentrate (WPC) — 70–80% protein with a little lactose and fat; the most affordable and tastiest. Enough for most people.
• Isolate (WPI) — 85–90%+ protein, almost no lactose or fat. For lactose sensitivity, cutting and strict diets.
• Hydrolysate — 'pre-digested', absorbs fastest, costs more and tastes slightly bitter. Not needed by most.

For muscle growth what matters is your daily protein total, not the type. On a budget — concentrate; if your stomach complains — isolate.