the end, edge, or outer limit of something: the point in space where a thing stops
This word marks where something runs out. Its core picture is a boundary point: the rim of a curtain, the tip of a staff, the outskirts of a camp, the far border of a land, or the distant horizon where the world seems to stop. The same noun covers all of these because they share one idea, the outermost point of whatever is in view.
From that single idea the word stretches across a wide range of scale. Up close it names the edge of an object you can hold or the border of a town you can walk to. At the largest scale it names the farthest reaches of the earth and sky, places too remote to visit, used to say "as far away as anything can be."
A third use grows out of the same picture in a surprising direction. To speak of something "from its end" came to mean taking it in from one extreme, and so the phrase can point to the whole of a group rather than just its rim, much as English "from end to end" means the entirety. Context, not the word itself, tells you whether a near edge, a far limit, or a whole sweep is meant.