Level 2 market data is also known as the order boo

Level 2 market data is also known as the order book. When orders are placed, they are placed through many different market makers and other market participants. Level 2 will show you a ranked list of the best bid and ask prices from each of these participants, giving you detailed insight into the price action, including the market depth. Knowing exactly who has an interest in a stock can be extremely useful, especially if you are day trading.