Wikipedia
A floor trader is a member of a stock or commodities exchange who trades on the floor of that exchange for his or her own account. The floor trader must abide by trading rules similar to those of the exchange specialists who trade on behalf of others. The term should not be confused with floor broker. Floor traders are occasionally referred to as registered competitive traders, individual liquidity providers or locals.
These traders are subject to a screening process before he or she can trade on the exchange. The people who operate as floor traders are in an open outcry system that has slowly been replaced by automated trading systems and computers that work in the same fashion as humans without the interaction of people buying and selling stocks.