Zoning players is an integral part of the laning phase in League of Legends. If you can manage not only to zone the enemy champion(s) but also last hit you will become farmed really quickly while your enemy will be getting no gold and no exp due to being out of range of exp and last hitting. If you only last hit, the minion waves will continue to stay in the same place instead of moving towards either your tower or the enemy tower allowing you to stay safe by not having to over extend towards the enemy tower to kill minions.
Video by Shureliya
