Xorg (commonly referred to as simply X) is the most popular display server among Linux users. Its ubiquity has led to making it an ever-present requisite for GUI applications, resulting in massive adoption from most distributions.

from the Arch Wiki

Sometimes, one wants to change some behaviour of a keyboard. This is very sane: CapsLock, for example, is arguably useless, and it occupies a real important place in the keyboard (notice how you can reach it with your pinky left finger; now, try to use the same pinky to press the left-side Ctrl key). This was an immediate necessity for me, and so was to have different keyboard layouts (the English/American layout is, I find, so much better for programming, with so many symbols readily available).

The Arch Wiki resource on keyboards is very helpful.