I am not a trader myself but am trying to educate myself about trading.
I notice that in most articles and videos about technical trading, an illustrative graph is displayed showing the latest price of a stock. This price (call it P) I presume corresponds to the latest price agreed between a buyer and a seller. Also presumably, there are a collection of currently-unmatched buyers and sellers that are hoping to buy/sell at prices slightly above or below P. They may declare "I have X amount of shares to sell if anyone will buy them for \$Q each" or "I will buy Y shares if anyone will sell them for \$R each".
I don't know what these declarations are called, are they "orders"? I presume that many orders are never matched, or are only partially matched or may get cancelled.
My main question is: can everybody see the current set of unmatched orders? Or is it only the people that actually run the exchange? And if it is visible, is it the kind of data that is readily available at reasonable cost or the kind of thing that only the big banks and HFT traders would ever get access to?