You first want to understand some of the terms used, like realtor, real estate agent and broker. A realtor is someone who is licensed by the National Association of Realtors (NAR) and is bound by a Code of Ethics. Someone who can't use the label realtor, but is a real estate agent or broker, may not have this type of license. Generally, the terms "real estate agents" and "brokers" are used interchangeably. However, these terms may also be used to describe the relationship between the agency and the person with whom you're working.
More important than the terms (although you do want to know how or where your real estate agent has received his or her license), is the scope of services you'll be getting. You can use either a full-service agent or a discount service. If you use a full-service real estate agent, you should expect the agent to handle it all, from A to Z. The agent will take care of prepping the house, which can include having professional photos taken; the agent will also develop professional marketing materials, manage all the showings, actively market your home, and handle the negotiations and legal process. Of course, you'll pay a full commission to the agent for this service.
However, if you want to pay less in commission, you can use a discount service. The commission rates for a discount service can be as low as 2-4.5 percent and what you'll get for that rate will vary. Discount services will usually list your house on the Multiple Listing Service (MLS), which all real estate agents use to find houses for sale. They should also pre-screen for qualified buyers. However, you will have to manage all the showings, which can take a lot of time and energy. You should also know that some buying agents will be reluctant to bring potential buyers to your home since they know you're paying less in commissions, which they often split with the seller's agent.