Anne Lamott refers to the first draft as the down draft and the second draft as the up draft, because you get it down then fix it up. Stephen King calls the first one the "closed door" draft and the second the "open door," the first being for you alone and the second for others to see.
You should write at least three drafts, however. Author Robert Stone insists on this number, explaining that in the first stage he writers very quickly, recording things as they come off the top of his head. The second draft he approaches more intensely, revising the diction and syntax to give it literary power. And the third draft he uses to make it all sound like it's just coming off the top of his head.
Writers early in their careers will need many more than three; ten is advised.
The longer you work and the more you generate text, the sooner you'll produce a manuscript someone wants to read.
What is written without effort is read without pleasure.