The term Ball tampering refers to the illegal or abnormal activities conducted with the ball during a cricket match. According to cricket law the players can only put saliva they cannot mistreat the ball shape.
Cricketers mostly uses creams and other lips products to make the surface of the ball more shinny or uses their nails and bottle caps to change the shape of the ball which is consider illegal in the law of cricket.
Crickets makes the ball shinny to increase the weight of the ball from the shiny side which helps the bowler to swing the ball more with less effort. Ball tampering is against cricket laws therefore strict punishments are also applied to the accused.
Sometimes if the case is not more sensitive the player is only charged with his match fee or he/she is also banned from playing few matches and if the issue is sensitive the player has to face years of ban from the international cricket council.