While tooth type, size, and separation apply to the entire zipper, the locking attribute applies just to the slider. A locking slider has a mechanism that keeps it from sliding down the closed tape.

Locking sliders have a pin that sticks into the zipper tape that's disengaged by pulling the tab. This mechanism is visible inside the slider crown.

Non-locking sliders don't have this mechanism.

In practice, a locking zipper won't move when there's tension on the zipper and they're often found on center front zipper lines.

As a general rule, non-locking zippers are on coated/waterproof zippers and pocket zippers.