Agent
Part of speech: noun
Definition: One who exerts power, or has the power to act; an actor. One who acts for, or in the place of, another (the principal), by authority from him; one intrusted with the business of another; a substitute; a deputy; a factor. An active power or cause; that which has the power to produce an effect; as, a physical, chemical, or medicinal agent; as, heat is a powerful agent. In the client-server model, the part of the system that performs information preparation and exchange on behalf of a client or server. Especially in the phrase “intelligent agent” it implies some kind of autonomous process which can communicate with other agents to perform some collective task on behalf of one or more humans. The participant of a situation that carries out the action in this situation, e.g. "the boy" in the sentences "The boy kicked the ball" and "The ball was kicked by the boy".
Example sentence: I went to university for a year, and I'm not one for schooling and have no enjoyment sitting in a classroom all day and ended up going to live in England for two years, just to travel. I worked in a bar in a hotel for a couple of years and had no intention of becoming an actor. That's where I met my agent.
Broker
Part of speech: verb
Definition: To act as a broker; to mediate in a sale or transaction.
Part of speech: noun
Definition: A mediator between a buyer and seller.An agent involved in the exchange of messages or transactions.
Example sentence: When I was an institutional broker in a former life, I was a believer in the merits of using technical analysis. I found that it was a very useful tool that complemented the much more mainstream tools generically referred to as fundamental analysis.