Many things contain protein, however when you are training and trying to build muscles mass, you need to have a protein with high amounts of: All 18 amino acids, 3 Branch Chain Amino Acids and Glutamate. The LA Whey has all of these. Normal meat and vegetables do not. This is why when people take LA Whey 2-3 times a day, they build a much more muscular body in record time.
If you have time, please read: What is Whey Protein?