The MLS is a local or regional service that compiles available real estate for sale by member brokers along with detailed information brokers and agents can access online. Local MLS organizations have their own rules and systems for providing listing information. Over half of the MLSs in the United States are affiliated with the National Association of Realtors (NAR); in other cases, MLSs operate as private businesses but with oversight from major local brokers. Some MLSs publish their own websites for consumers to access listing data directly from the MLS, but most share data by offering a data feed for member brokerages to build their own websites
