Final answer:
An agency relationship in real estate usually forms between the seller and the real estate broker. The broker represents the seller's interests in the transaction and has certain fiduciary duties. Customers are potential buyers and sub-agents work under brokers.
Step-by-step explanation:
An agency relationship is typically created between a seller and a real estate broker when the seller hires the broker to represent them in selling their property. The broker, in turn, can operate through real estate salespersons. This relationship involves duties such as loyalty, care, and obedience on part of the broker to act in the best interests of the seller. A customer is generally someone who is interested in buying the property, while a sub-agent works for the broker and helps in selling the property.