Utilize your financial knowledge, give your answer or opinion to the input question or subject . Answer format is not limited.

Buy/Selling prices at the stock exchange represent someone Selling/Buying at that price?
You don't see Buying and Selling. You see Bid and Ask. Best Bid--Highest Price someone is willing to pay to buy a stock. Best Ask - Lowest price someone is willing to accept to sell a stock. As for your second question, if you can look up Accumulation/Distribution Algorithm and Iceberg Order, you will get basic idea.