The management of a hockey team is, depending on the level of the team, more or less big in size. For most professional teams, a typical executive staff will be made up by the owner, the president, the general manager (who is often executive vice-president as well), a director of player personnel and a director of player development; many of these executives will have their assistant.
Their roles are to literally manage all the aspects of the team outside of the game itself, from player recruiting to finances.