What Is a Draft in Writing
A draft is a complete state of the text, start to finish, however rough it is in places. The word describes completeness, not quality: a first draft can have thin dialogue, a missing subplot, and an ending the writer isn't sure of yet, and it's still a draft in the full sense, because it runs all the way from the opening line to the last one. What it isn't is a plan for a text, no matter how detailed that plan gets.
Where the confusion comes from
A richly developed outline sometimes gets called a "first draft," especially once it's long enough to feel substantial. That blurs something useful. An outline, however thorough, still describes the book from outside it; a draft is the book itself, in its own sentences, with its own rhythm, however unfinished that rhythm is. The difference matters because a plan can be endlessly perfected without ever producing the thing a plan is for.
How this shows up in a real novel
Gustave Flaubert's drafting process for Madame Bovary (1857) is documented in his own letters as famously slow: pages rewritten dozens of times in pursuit of what he called le mot juste, the exact right word, sentence by sentence, sometimes producing only a handful of finished pages in a week. What his surviving drafts show is a text built in layers, each pass still a complete draft in its own right, however far from finished, rather than notes waiting to become one.
While you're drafting
A first draft only has to reach the end; the impulse to perfect a scene before moving to the next one usually does more to stall a manuscript than any actual weakness in the writing itself.
Questions
Does a draft have to be good to count as a draft? No. The word describes whether the text runs from beginning to end, not how strong any part of it is. A rough first draft is still fully a draft.
Is a detailed outline the same as a first draft? No. An outline describes the book from the outside, in summary. A draft is the book itself, written in its own sentences, however unfinished those sentences still are.
How many drafts does a novel usually take? There's no fixed number, and it varies enormously by writer and by project. What stays constant is that each pass, however different from the last, is still a complete draft rather than a set of notes.