A professional sales person who sells houses, condominiums, and cooperative apartments (co-ops) for a living. The real estate agent legally represents sellers, even if he or she is working with buyers to show them properties. Real estate agents are paid on a commission basis calculated on the selling price of the house, which may be as high as 7 percent. The seller pays the commission. However, buyers can contractually hire their own agent to advise them on the buying process. In that case a fee, which might be a commission based on a purchase price, is paid by the buyer.