A Board of Directors has three primary "big picture" responsibilities. The second is Fiduciary Responsibility. A Board serves as trustees of the assets to assure that the organization is managed well and has a sound financial situation. Boards must maintain financial accountability for the organization. For a non-profit, the Board is the caretaker of the contributions the organization receives from donors and sponsors. The Board's decisions, if not done with reasonable care, can put the organization in a risky situation.
This article from BoardSource provides excellent information on financial accountability: Fiduciary Responsibilities of Board Members