Rather than thinking of numbers of buyers and selling, view it as a negotiation. All of the buyers are say what they will pay and the sellers are saying what they will accept. When a buyer and seller come to terms the stock is traded. The price will go up or down depending on what they agreed to relative to the last price.

As to the one buyer, one seller sometimes there is one party on one side of the trade and multiple parties on the other side. Example: if I want to buy 1000 shares of a stock there could be several different sellers involved.

Yes, there is a buyer for every seller. But at what price? That's the critical factor that determines "up" or "down."

Well... simply put, you're entirely right. I have an apple - and you want it. If you and three other people want my apple, then I can raise the price because I can get it.

Or if nobody wants my apple, I drop the price until somebody wants it... And then if nobody wants it, I went broke and my apple is worthless.

problematic thing look in google and yahoo that may help

I know that prices increase when there is more buyers than sellers and prices decrease when there is more sellers than buyers. But shouldn't the number of buyers always equal the number of sellers? Because if i sold a stock that would mean someone had to BUY it, and therefore there is one seller and one buyer on every deal, what am i not understanding?