The Vedas contain perfect knowledge, which includes all kinds of knowledge for the human society, not only on this particular planet but on other planets as well. It is understood that military art is also necessary knowledge for the upkeep of social order, as is the art of music. All these groups of knowledge are called the Upapurana, or supplements of the Vedas. Spiritual knowledge is the main topic of the Vedas, but to help the human beings spiritual pursuit of knowledge, the other information, as above mentioned, forms necessary branches of the Vedic knowledge.