A fourball match consists of two teams of two players competing directly against each other. Each golfer plays his own ball throughout the round. A team's number of strokes for a given hole is that of the lower scoring team member.
In stroke play, the scores are added normally, and the team with the lower score at the end of the match wins.
In match play, each hole is won by the team whose member has the lowest score on that hole, and that team is awarded a point for the hole. If the teams tie for a hole, the point for the hole is divided between the teams. At the end of the match, the team with the most points wins.
It is also known as "best ball," or more properly "better ball."