What is meant by vegetable protein powder?

What is meant by vegetable protein powder? Is a sprouted brown rice powder acceptable? I can't eat whey and prefer not to have soy.

Vegetable protein powder is just that; relatively pure protein in a powder form derived from vegetables. It is the protein extracted from the rice or peas and therefore uses only a fraction of the nutritional composition of those vegetables, since most vegetables do not contain a high percentage of protein. Also, for there to be a high-quality and complete protein, additional amino acids are generally added. Just using brown rice powder would give a tiny amount of protein and a huge amount of sugar forming starch.