Billiard is a type of shot especially made in Cue sports mainly in snooker, carom billiards, pools and so on. In recent day sports, the game is categorized into many subdivisions that include, carom billiards, pocket billiards, and Dynamic billiards. The game of billiards was brought to America in the 19th century. The previous versions of pool games used to be played with a set of 15 multi-colored balls. With the changes in rules the game was reduced to 8-ball and 9-ball pool game with similar multi-colored balls.

Different types of games incorporate different types of rules. The general rules that imply to pocket billiards emphasizes on racking the balls in a triangular shape and the apex ball to be spotted on the foot spot and all the balls should be positioned behind the apex ball. The primary authentic shot is to strike the cue ball with the cue tip, failing which results in a foul. If a player fails to strike the Cue ball, the opportunity passes on the other player who needs to strike the Cue ball correctly. If a player commits foul then the playing inning ends, and if the player performs an invalid or illegal stroke then the already balls that are pocketed is not counted. The position of the ball is judged based on the base where it is placed.

A ball is considered to be pocketed correctly if on a legal shot the ball drops off the table surface and remains in the pocket. If the ball rebounds back to the surface of the table after being pocketed is not considered legal. Touching any ball with the Cue ball while on hand is considered a foul. During the course of play if a player fails to pocket the balls in legal shots, his inning ends and the other player gets the chance to start his inning. The players are not allowed to use any external means to measure the width, distance and the size of the balls on the table.