The board of directors is the group of people that runs/owns a football club. It is made up of a chairman and a number of other people such as a managing director. On FM, most large clubs have a board of directors, whereas most smaller clubs just have a chairman.
If a club hasn't got a chairman or any directors set up, news items will refer to the club's "board," by default, without mentioning the names of any staff.
In Football Manager[]
Directors were included for the first time in Championship Manager 3 and have been a feature of the game ever since. Up until Football Manager 2007, directors (and other club officials) could only be changed using a data editor but from FM2007 onwards board takeovers can occur during the game.