What's the difference between low (trail) gaiters and high (mountaineering) gaiters?

Low gaiters cover roughly the ankle and top of the shoe, weigh ounces, and are aimed at keeping debris out during hiking and trail running. High gaiters extend to just below the knee, are usually built from heavier waterproof or coated fabric, and are designed for snow, postholing, brush, and crampon use. Expert testing in the candidate set treats them as different product categories rather than substitutes.