In commerce, a broker is a party that mediates between a buyer and a seller. A broker who also acts as a seller or as a buyer becomes a principal party to the deal. Distinguish agent: one who acts on behalf of a principal.

A brokerage is a firm that acts as a broker.

See also:

• Real estate broker
• Stock broker
• Ship broker
• The Broker.

In computing, a broker consists of software which mediates between two objects: typically between a client and a server or between a repository and a requestor or caller. See for example:

• message broker
• object request broker
• storage resource broker