In the National Football League, the general manager (GM) of a team typically controls player transactions and bears the primary responsibility on behalf of the team during contract discussions with players.
The general manager will in many cases have oversight of the entire football department, typically reporting to the team president/CEO and/or owner. However, some teams have the GM act in advisory role with the head coach having oversight of the football operations (including the GM).
Some teams (e.g. Dallas Cowboys, New England Patriots, Cincinnati Bengals) do not have official general managers instead have a de facto GM. Similar positions include President of Football Operations. Bill Belichick of New England Patriots is an example of a coach who is the de facto general manager; he has never been officially named or granted the title of general manager but he has the final say in football operations. Dave Gettleman, current GM of the New York Giants is an example of a person with the sole title of General Manager.