Technically, the art of writing is putting words to paper. Colloquially, it has become slang for composition; the art of composing prose and poetry, which in many traditions was not written down.
I never stop writing (re: composing), it's a constant day long mental activity. More often than not, I am uninspired to write it down permanently; posterity be damned.
I write most frequently about concepts of existence and reality, through observations and theories on a formula of omniversality. [aka. my realization of the god formula in my own bastardized definition of existence (re: omniverse)].
I write here when the mood strikes me, but it's only the smallest smidgen of anything I actually work on. I occasionally jot an entry and never publish it. Some things are meant just for me.
Does that explain it?
;p