Board of Directors (BOD)
Shareholders usually elect a board of directors. The members can be shareholders within that company and/or be paid for their services. They have legally defined responsibilities and can be held responsible for their errors. It's not a flexible structure and it's harder to manage such boards, but the knowledge and expertise they can bring to a company can make a real difference. They can help with networking, support and validate the decision making, setting broad goals and so on. They represent both management and shareholders' interests and can include both internal and external members.