It is organised to say things about things.
Language is an intergral part of every human society.
There's no reason to think that volcabulary, for example, is innate and unlearnable. This is what Chomsky called the Poverty of the Stimulus. But humans can tell whether or not the sentences are gramatical, and that's what Chomsky was trying to explain. Well, even learned skills have a brain basis, and could be disturbed or lost because of a brain injury. No one knows how to do the arithmetic for the number of connections, so those are just guesses.