A Seller Listing (also referred to as a Property Listing or Home Listing) represents an agreement between a real estate agent and a property owner who wishes to sell. As a part of their buyer community, in exchange for a commission.
Almost universally required to be in writing by rules, laws, and regulations (using an "Exclusive Listing Agreement"), a Seller Listing arrangement is generally of the "Exclusive Sale" form, where the Listing Agent earns a commission even if the Seller finds the Buyer. There are also "Exclusive Agency" agreements where the Seller may try to find the Buyer and avoid some, or all, of the Agent's commission.
Finally, though little-used since the late 1980s, there are "Open" and "Private Exclusive" Listings, which are self-described. Seller Listings (exclusives) are entered into the centralized Multiple Listing Service (MLS) in most areas of the United States.