Most states require real estate sales professionals to be licensed by the state, so that they can control to a central authority consumer education and experience requirements and resolve problems.
The terminology used to identify real estate professionals when you close a little from state to state. Brokers generally are not required to have more education and experience than real estate salespersons or agents.
The person you normally deal with a real estate agent or salesperson. The salesperson business licensed by the state, but must work for a broker. All listings are placed in the broker's name, salesperson's note.
A broker can deal directly with home buyers and sellers, or can have a staff of salespersons or agents working for him or each.