Referee
Sir.
The second referee is called the 'down referee,' who watches for players who cross the line of the court, contact the net, or setters who jump/back row attacks. They also signal for player substitutions in games, and work with the 'up referee' to call balls out and in.
the net the players the referee the field the ball
A referee can only show cards to players, and since the referee himself is not a player he cannot receive red cards. A referee may remove themselves of their duties if they are unable to continue.
It consist of when you are yelling at the referee for something.
So he can be distinguished from the rest of his players by, the players on the pitch, the referee and officials and the fans.
There are 25 professionals on the field during a game - 22 players, 2 linesmen and a referee.
American football has a few referee's at every game to monitor each play at all times.
In the college game, a team has to forfeit the game when they are down to one eligible player--- unless the referee believes they could still win the game. In the NBA, teams must have five players on the court, and there is a rarely-used procedure where players can come back into the game if their team runs out of players. If a player comes back in after fouling out and gets another personal foul, his team is assessed a technical foul in addition to the personal foul.
Making sure players have practiced enough - apex :)
Alternate captain. Hockey players with a "C" (captain) or an "A" are the only players that are supposed to communicate with referee's on the ice.