All good writing is prewriting.
Even though rewriting is one of the most important aspects of the writing craft, there is another process that's equally important.
You have probably heard the phrase, "All good writing is rewriting."
In case you have doubts, it's true. To deliver a good piece of writing you have to rewrite it several times. It's just part of the craft. It takes at least two or three rewrites to get a text to hit the mark.
Besides rewriting, though, there is another process that's equally important. Perhaps even more. It's prewriting.