https://theirboard.com/whats-the-difference-between-the-board-of-directors-and-an-advisory-board/
A board of directors is an institution of individuals who are responsible for the management, control and direction of the organization. They are accountable for the legal obligations of a company and are held to a high standard of accountability. If they fail in their obligations to their fiduciary obligations they could be personally accountable.
A group of people who advise and coach a business is called an advisory board. The advice they provide is more hands-on, and their focus is on growth, development and strategy, as opposed to reporting governance, governance, risk management and avoiding downside risk.
Idealy, an organization should clearly define the purpose of its advisory board in all official documentation such as meeting minutes and the way of communication to avoid confusion. This will ensure that they do not accidentally enter into the territory of a board of directors which could result in grave legal implications if they fail to meet their fiduciary duty.
The distinction can get somewhat unclear in practice, with organisations sometimes referring to their advisory boards as “the board.” It’s a good idea to put this in writing to ensure of clarity and to avoid any unintentional mistakes. A formal written statement that defines the role of an advisory board can reduce confusion among the people involved. This is especially useful when members of the board were previously part of an advisory board or are new to the organization.