A "final draft" is a document
that is thought by its author
to be in its final
form. After a "rough draft
" has gone through a cycle of review
(usually several such cycles occur), the final draft is the end result. Aside from being free of spelling
and grammatical errors
, a final draft should be as clear and refined as possible.
As this is somewhat subjective, I look at this document state as being slightly mythological, although I suppose it's merely a matter of semantics (a document becomes a final draft once you refuse to revise it any further, for example).