A no-ball occurs when the bowler breaks rules like overstepping the crease or throwing an illegal delivery. Batters cannot be dismissed normally on a no-ball, and one run is added to the batting score.
For instance, a bowler overstepping on a crucial delivery in an ODI can give the batter a free hit. Understanding no balls helps batters play safely, and bowlers avoid giving away easy runs.
Pro-Tip: A free hit after a no-ball allows the batter to play any shot without fear of getting out.