Essential amino acids cannot be made by the body. You must get them from complete protein foods or combinations of incomplete vegetable foods. There are 9 essential amino acids: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, tryptophan, and valine.
/bcaa's on the other hand are metabolized in the muscle instead of the liver. This is what makes them such easy prey when dieting, why they can indeed be useful at this time. These are but3, L-Valine, L-Leucine, and L-Isoleucine.