What is Zoning?
Your zone is the area you are able to control with your hero. Zoning is the act of controlling your enemy's positioning and/or making them afraid of entering your zone. Zoning occurs when you push enemies back from creeps by making them fear your zone. This is benificial because they will have a much harder time funding items mid and late-game due to not being able to last hit creeps for money. Additionally, by pushing enemy champions far back enough, you can even deny them experience from dead creeps without denying them. Both of these things together can be extremely advantageous throughout the game, as your opponents can be both undergeared and underleveled.