What is a real estate agent?
Real estate agents have been licensed by their state to help people buy and sell property. People licensed by the state have to have completed courses in real estate, including coursework in real estate law, real estate financing, and listing, according to the National Association of Realtors. 

A real estate agent can represent buyers and sellers in several different ways and you need to be very cautious in choosing the level of representation that your agent will provide to you. The choice is yours. An agent can represent either a buyer or seller exclusively, or he or she can represent both parties in the same sales transaction (called "dual agency" since the broker acts as the agent for both buyer and seller. 
Your lawyer can assist you in determining how to assess the benefits and dangers of the different levels of representation, including the lowest level of service, and the one to be most cautious about - dual agency).

[A broker is a person licensed to own a real estate firm. Realtors are real estate agents who belong to the National Association of Realtors]. 
 
What does a real estate agent do?
The purpose of having an agent when purchasing/selling a home is to help you as a buyer/seller, make good decisions! Your agents counsels you through the whole process. 
The agent working with a buyer or seller needs to take on three roles; 
- first educate you about the process, and the market,
- second consult or counsel you on decisions, 
- and finally aggressively represent you interests. 
  
When an agent lists a property and represents the seller, his duties break down like this: 
Seller Buyer
- Must always act in seller's best interest  - Sell you a House 
- Obtain the best price and terms for the seller - Be Honest 
- Be the eyes and ears of the seller, relaying any information from you that may help the seller negotiate. - Disclose material defects 
- Keep all information and conversations with the seller confidential  - Disclose that they work for the seller 
  
When an agent represents you as a buyer, his duties break down like this: 
Seller Buyer
- Be Honest  - Must always act in your best interest
- Disclose that they work for the you as the buyer - Obtain the best price and terms for you 
- Be your eyes and ears, relaying any information that may help you negotiate.
- Keep all information and conversations with you confidential