Marketplace (n): An open area or square in a town where a public market or sale is set up. The world of business and commerce.  A situation or place in which values, opinions, and ideas are put forward for debate or recognition: a marketplace for new ideas; the literary marketplace.

Market (n.) : A public gathering held for buying and selling merchandise. A place where goods are offered for sale. A store or shop that sells a particular type of merchandise: a vegetable market.  The business of buying and selling a specified commodity: the soybean market. A market price.  A geographic region considered as a place for sales: grain for the foreign market; the West Coast market. A subdivision of a population considered as buyers: cosmetics for the upscale market.  The opportunity to buy or sell; extent of demand for merchandise: a big market for gourmet foods. An exchange for buying and selling stocks or commodities: securities sold on the New York market.  The entire enterprise of buying and selling commodities and securities: The market has been slow recently.

v.tr. To offer for sale. To sell.
v.intr. To deal in a market.  To buy household supplies: We marketed for a special Sunday dinner.
in the market: 1. Interested in buying: We are in the market for a used car.
on the market: 1. Available for buying: Many kinds of seasonal flowers are on the market.  2. Up for sale: They put the family business on the market.