What is "Occam's razor?"

It's the rule that says that the best explanation for a phenomenon is usually the simplest one that makes the fewest logical leaps.

It's the rule that says that if you hear hoof beats, think of zebras, not horses.

It's the rule that describes how artifacts can fall down the cuts made by animal burrows to great depths in the soil.

It's the rule that explains why the most likely explanation for stones like the one pictured in Figure $2\mathrm{.}7$ is that they were made by elves.