Refers to the body of directors as a group, not the meeting itself.
The board of directors appointed a new president.
board meeting; meeting of the board of directors
Refers to the meeting itself. Context usually makes the distinction clear.
We plan to discuss that matter at next week's board meeting.
It was decided that an emergency board meeting would be held next week.
The appointment of the new president was decided at the board meeting.
Outside directors also have a duty to attend board meetings.
This investment plan must obtain the board of directors' approval.