Is the One just a prophecy for "free humans"? If not, to whom else was this person important? What did the machines have to do with him?
I know this question is very broad and has multiple questions in them. But, I left it in the same state because of one precise reason, I may not recall all the relevant facts about the Matrix to narrow it down, but would like the answer to be consisting of that information. I guess that's too much to ask here and thus I am reducing the breadth of the question by adding some thoughts related to it:
If the One is the one for whom the free humans have been waiting on to save the world kind of a thing, the existence of the Oracle becomes a bit mysterious. The architect telling Neo that there have been several 'One's before him makes me feel that the machines too wait for the One to appear so that they can achieve some hidden goal of theirs at that time.