Estate agent is a United Kingdom term roughly synonymous with the United States term real estate broker, a business that arranges the selling, renting or management of homes, land and other buildings. However in many instances, estate agents are mainly engaged in the marketing of property available for sale and a solicitor is used to exchange contracts.
Note that in the United Kingdom, real estate is generally referred to simply as property.
Origin
The term originally referred to a person responsible for managing a landed estate, while those engaged in the buying and selling of homes were house agents, and those selling land were land agents. However, sometime during the 20th century 'estate agent' started to be used as a generic term, perhaps because it was thought to sound more impressive.