What does the term ‘backing up’ mean in cricket?

What does the term ‘backing up’ mean in cricket?

After a fielder chases the ball, another fielder placed at a further distance also moves into position so that if the fielder misfields the ball, the damage done is minimal. This is called backing up. Backing up is also done to support a fielder receiving a throw from the outfield in case the throw is errant or not caught. Backing up is done to avoid ‘overthrows’. The non-striking batsman leaving his crease during the delivery in order to shorten the distance to completed one run, is also called backing up. A batsman ‘backing up’ too far runs the risk of being run out.