There are two types of real estate licenses - a salesperson's and a broker's. Most of us come in contact with the salesperson, or agent. But the broker is the invisible grease in your purchase or sale.

Agents with a real estate broker's license must meet higher education and experience standards than those with a salesperson's license.Your real estate agent may have either a salesperson's license or a broker's license. A broker licensee may either operate independently or work for another broker.

Agents who have a sale's license must work under the supervision of a broker. This is done to ensure that you have access to the same education and experience standards whether you work directly with a broker or indirectly with the broker through the broker's agent.

Although your agent may be a broker working independently, it's far more likely that the agent will be part of a small, medium or large real estate office. I've seen excellent agents working in all these modes. What's important is the quality of service you get - not the size of the agent's office.

Everything your agent does or fails to do is the broker's responsibility. In a crisis, the success or failure of your transaction may depend on your broker's backup support.

Now let's see what your broker does:

- Public relations. Good brokers strive to develop, maintain and improve relations between their offices and everyone their offices work with in your community. This includes other real estate offices, the local Board of Realtors, lenders, title companies, contractors, politicians, city government agencies and civic organizations.

One criterion for picking your agent should be the reputation of the broker's office in your community. The office's good or bad image will be apparent in the comments you'll hear from people you talk to during your agent selection process. If people say the agent is great but have negative comments about the office, eliminate the agent.

There are two reasons why you should select a firm with an excellent public relations image. You want people to do business with you because of your agent's office - not in spite of it. The last thing you need is guilt by association. Furthermore, you'll need to piggyback on your broker's good will if the going gets rough. A broker with great business relationships can work miracles for you in a crisis.

- Adviser. Good brokers stay current on everything affecting their offices' segment of the real estate market. They monitor constantly changing areas such as federal and state tax codes, local zoning codes, real estate law, and mortgage interest rates. Then they brief their agents on the probable impact of these changes so the agents can pass the information on to clients.

Anyone can read you yesterday's newspaper. One mark of good brokers is their ability to make accurate forecasts of what will probably happen tomorrow. This is what you need to put yourself in control of changing situations. Call your broker whenever you need more information in these areas than your agent can provide.

- Judge and jury. The buck stops with the broker for all nasty or messy decisions. Real estate commissions, for example, are negotiable at any time during your transaction. You'll probably have to get your broker's approval for any commission reduction since agents rarely have the authority to reduce commissions.

One guess who makes peace between two agents in the same office who both claim to be the first agent that worked with you. One guess who gets called when your agent has a personality conflict with the agent representing the other party in your transaction. One guess who you should call if you have problems with your agent. Your broker, that's who.

Call your broker if you and your agent are stymied by a tough problem. Good brokers take care of difficult problems immediately.