Final Fantasy X question?

I own the first final fantasy for the PSP and the tenth installment on the PS2. In the tenth, I have absolutely no idea what the F**k is going on. Does this game have any relevance at all to the first game, or the seventh, or something? Or is this a completely parallel universe and the FF games have nothing to do with each other? Because I swear that Zanarkand was a small village in the first FF......................