This is actually not only with ranged characters but with every character.This is called "Stutter-Stepping" and is more or less a habit of high elo players that actually comes with some benefits:
- Training your Timing:
You should always Click the turret at the exact same time as your AA timer resets.
- Training positioning:
You reposition yourself every 0.7 seconds.
- Dodging skillshots:
It's easier to not get hit by anything if you constantly move when attacking a turret.
- Stay in the flow of the game:
If you attack a turret and you do pretty much nothing for 10 seconds that's fatal! You need to be focussed for 100% of the time if you want to win and always clicking helps doing so.
Now the 4th point is pretty much the most important one. High elo players usually stutter step because of this point. Also the habit exists because of this need of focus. A high elo player will have a lot more APM than a mid-low elo one and if he doesn't do anything for 2-5 seconds his playstyle won't be as good as before for a certain amount of time.
So this is not kiting. Kiting is running away from a target while damaging it. For league champions Ashe/Vayne/Ezreal would be a good example for excellent kiters but you cannot kite a stationary target like a turret.