There are two standard scoring systems used for volleyball known as sideout scoring and rally scoring. In the sideout scoring system, the only team that can score points is the team that serves the ball. If the non-serving times wins the point, they do not score a point but instead only earn the right to serve for the next point. With rally scoring, on the other hand, either team can score regardless of who the serving team is.
Teams score points when the opposing team fails to return the ball over the net, hits the ball out of bounds or commits an infraction such as touching the net or hitting the ball too many times. From another perspective, a team can earn points by hitting the ball and making it hit the floor within the boundaries of the court. If the ball hits the line, it is counted as in.
For sideout scoring games, the first team to score 15 points wins. For rally scoring games, the first team to score 25 points wins. However, unless otherwise specified, games have to be won by at least two points in either scoring system.
As of 2015, the rally scoring system is the predominant scoring method used. The sideout scoring system was used primarily until 2001.