Stoppage timeAdded time belongs to the half
The referee allows time for substitutions, injuries, disciplinary sanctions, VAR checks and reviews, goal celebrations, time-wasting, medical stoppages, and other significant delays. The fourth official shows the minimum added time, but the referee may increase it if more time is lost.
Extra timeExtra time is a competition rule
The Laws of the Game allow competitions to decide how tied matches are resolved. In knockout football, the common format is two 15-minute periods of extra time. There is no modern golden goal in ordinary top-level competitions unless a specific competition rule says otherwise.
Penalty shootoutPenalties decide the outcome, not the match score
Kicks from the penalty mark are used to determine the winner when required. They are not the same as penalty kicks taken during normal or extra time, and the shootout result is normally recorded separately from the match score.
Common argument"The referee has to stop at the number shown"
No. The number displayed is the minimum additional time. If a goal celebration, injury, substitution, VAR review, or other delay happens during added time, the referee can add more.