Stutter-stepping

Stutter-stepping is a movement technique utilized increase a champion's attack efficiency. This is primarily practiced by because they need to output as many basic attacks as possible.

Technique
A basic attack consists of three animations: Windup, Firing, and Backswing. A movement command can be issued to cancel the current animation, except during the firing animation when the attack is launched (Ranged champions usually launch a projectile). When set to attack, a champion will automatically pursue their target if it falls out of range, but only after their entire attack animation completes. The time it takes is very dependent on, which can be too long to keep up.

If a player manually issues a move command right after their attack fires, they will immediately cancel the backswing animation and start repositioning. There is no penalty to canceling the animation, but opportunities may be missed if it is allowed to be played. This is called Stutter-stepping.

Benefits
By repositioning in between attacks, a champion can quickly move out of danger, or they can stay in range of a moving target. It also helps in farming efficiently while minions are dying very fast.

Stutter-stepping, Kiting, and Orb walking
Stutter-stepping is backswing animation canceling by moving right after firing an attack, kiting is doing this while running away.

Orb walking only applies to DotA: Allstars, it's when attack modifier abilities are used to engage. It doesn't count as a basic attack so it wouldn't draw minion aggro. It's called an orb walk because the items that grant these effects (orb effects) are commonly shaped into orbs.