Estate Agent
The formal definition of an Estate Agent might be as follows:
The person who acts as agent for you in buying, selling, letting and renting land or buildings and who will, for a fee or commission, provide services such as collecting rent, managing leased property, arranging surveys and valuing properties.
When it comes to residential property, estate agents are usually working for the sellor (the vendor) of the property. That's worth remembering when you're a purchaser - the agent sitting in front of you is selling to you!