An agent is a person who acts on behalf of another. In a real estate sale transaction, agents are present in the form of a Real Estate Broker or Salesperson who represents one (or sometimes both) of the principals, a Mortgage Broker who represents a buyer or borrower in obtaining financing, and an attorney or attorney-in-fact. The escrow holder is a limited agent for both of the principals in a sale transaction; their duty and obligation being limited to the content of the escrow instructions.