Primary Market: Term for the sources of art works initially sold to collectors, usually through galleries, dealers, and at artist's shows, the 'first sale' of a work of art.
Secondary Market: Term for sources of art works that have been sold before and are available again for sale in the market place. The secondary market provides liquidity for the art world. Estate sales and retirement down-sizing are the prime reason quality works of art appear on the secondary market. Auction houses, dealers, and galleries are participants in the secondary market.