Order flow simply means reading the demand and supply side of the market. Order flow replicates the transactions taking at the exchange on your chart and can show you in real-time the actual demand and supply at the exchange.

Auction Market Theory knows that short-term sellers may be selling to long-term buyers or short-term buyers to long-term sellers. In Market Profile we see the movement of price as an auction between buyers and sellers negotiating value during the day, across time frames.