Oh it's really simple.
First of all you need to know how "Orb walk" works, some call it kiting or attack move, back when i was young and full of energy it was called orb walk.
When a champion uses a basic attack you launch a sequence of frames
-Attack windup
-Attack connects (aka, the attack "goes out" your champion model, this is for ranged champions in particular)
-The attack animation finishes and basically it gives you the timer for when the next autoattack will be ready
Now, if you input any command, and we are talking about movement in particular here, you will "cancel" the third step, which is useless for what regards the autoattack, this way you can save time and not be locked in place for too long due to your own attack animation.
Since you are a human player, and thus an intelligent being <insert elo/intelligence jokes here>, you have control over your auto and you can decide to kite a target this way.
The jungle monsters are "stupid" because they're controlled by the game's AI, so if you walk back the monster will basically say "DURR, BOSS, THE TARGET IS ESCAPING, ME GOOD BOY, ME KILL CHAMPION HURR" and will attempt to chase you as long as you're in his leash range, if you learn how to walk back during the animation of their attack you can force them to waste time by canceling their attack command and input a movement command, this way you can reduce the overall damage you take from the camps and so have healthier clears since in the jungle managing your resources is the key to become an excellent jungler.
https://www.youtube.com/watch?v=5Y8bWaBtStw
This is an old ass video that shows you the wonders of orb walking, this is some smurf in silver on the korean server back in season 3.
For example, a personal favourite trick, in order to optimize the damage i have to receive from a jungle camp, if i have a champion with a stun i usually wait for the last frame before an autoattack hits me since this way i will force the jungle monster to start his animation from frame 1, and so i will waste his time as much as possible, if done correctly this can save you considerable amounts of hp since every auto will be like 70~ hp and a potion restores you 125~hp.
One last thing, when you're farming the jungle if you're single target attack the small monsters first so this way you will reduce the dps of the camp by a lot, if you have AOE let the aoe kill the small ones, some champions have particular ways to distribute damage so you will learn by yourself how to damage them.
If you have red buff try to spread the burn to every target so it will refresh more often and if you're fighting the infamous raptor camp attack the small ones ALWAYS no matter what since the damage from that camp is fucking insane.
