Soccer Girls

A standard adult football match consists of two periods of 45 minutes each, known as halves. Each half runs continuously, meaning that the clock is not stopped when the ball is out of play. There is usually a 15-minute half-time break between halves. The end of the match is known as full-time.
The referee is the official timekeeper for the match, and may make an allowance for time lost through substitutions, injured players requiring attention, or other stoppages. This added time is commonly referred to as stoppage time or injury time, and is at the sole discretion of the referee. The referee alone signals the end of the match. In matches where a fourth official is appointed, toward the end of the half the referee signals how many minutes of stoppage time he intends to add. The fourth official then informs the players and spectators by holding up a board showing this number. The signalled stoppage time may be further extended by the referee. Added time was introduced because of an incident which happened in 1891 during a match between Stoke and Aston Villa. Trailing 1–0 and with just two minutes remaining, Stoke were awarded a penalty. Villa's goalkeeper kicked the ball out of the ground, and by the time the ball had been recovered, the 90 minutes had elapsed and the game was over. The same law also stands that the duration of either half is extended until the penalty kick to be taken or retaken is completed, thus no game shall end with a penalty to be taken.
In league competitions, games may end in a draw, but in some knockout competitions if a game is tied at the end of regulation time it may go into extra time, which consists of two further 15-minute periods. If the score is still tied after extra time, some competitions allow the use of penalty shootouts (known officially in the Laws of the Game as "kicks from the penalty mark") to determine which team will progress to the next stage of the tournament. Goals scored during extra time periods count toward the final score of the game, but kicks from the penalty mark are only used to decide the team that progresses to the next part of the tournament (with goals scored in a penalty shootout not making up part of the final score).
In competitions using two-legged matches, each team competes at home once, with an aggregate score from the two matches deciding which team progresses. Where aggregates are equal, the away goals rule may be used to determine the winners, in which case the winner is the team that scored the most goals in the leg played away from home. If the result is still equal, kicks from the penalty mark are usually required, though some competitions may require a tied game to be replayed.