A more thorough explanation:

A fiduciary relationship is a type of relationship where one person has a duty to act in the best interest of another person. This duty is called a fiduciary duty. The relationship can be created in different ways, and it doesn't always depend on the parties' intentions.

For example, when someone hires an agent to do something for them, like sell their house, the agent has a fiduciary duty to act in the best interest of the person who hired them. This means the agent can't do anything that would harm the person who hired them, like selling the house for less than it's worth.

Another example is when a doctor treats a patient. The doctor has a fiduciary duty to act in the best interest of the patient, which means they can't do anything that would harm the patient, like prescribing the wrong medication.

It's important to note that the fiduciary relationship can end if the parties no longer intend to maintain it. However, the agent may still have some obligations to third parties that were created during the relationship.