[DexesTTP]

To simplify equations that create ratios between distance, time and energy. That's literally it. Using Planck units is a math trick to remove a bunch of constants from a bunch of equations.

The Planck length doesn't really have any known physical importance, at least no more than a meter does. There's some things that happens around a planck length (for example, the current theories predict that black holes need to be at least bigger than a planck length to exist, or alternatively the Planck length is the point where the quantum uncertainty completely overtakes any other classical theory) but particles can "move" distances less than a planck length (with lots of caveats, mainly because quantum uncertainty makes the notion of "moving" in the classical sense kinda weird and barely applicable, but still, they _can_).

A common belief is that the Planck length is kind of the "minimal distance" and start thinking that it's the "pixel of the universe" but there's no actual theoretical framework saying that. It's just a common misconception.

[GoblinSlayer]

Planck length is where quantum gravity overtakes a nonrelativistic theory, quantum stuff happens on a 25 orders of magnitude larger scale. For comparison: the universe is about as much bigger than you.