My cousin just started as a Real estate brooker, he is the person between the seller and buyer of a house. 
brokers can be very useful I understand but I dont really understand their job
He tries to match up people who are selling their house and people who wants to buy a house. 
so a broker and agent are the same thing
Estate agent is the term used in the UK. 
oh I see, so really the term is interchangable depending on where you live?
There are also differences as for the obligation, liabilities  and powers between an estate agent in the UK and a real estate broker in the US.  
oh interesting but since I am in the US and not in the UK hopefully I wont be using one to buy in the UK anytime soon
ALso, in the US, real estate brokers are called listing broker or listing agents. They are all the same.