Market depth gives a gist of real time market activity in a particular security. It gives an idea of the levels at which the orders are being placed. To view the market depth for a particular scrip, search for the scrip to go to the scrip info page. Market depth is where you can see the best 5 bids and asks under the Overview tab.
Orders indicate the number of open orders being placed for that particular price, while Qty indicates the quantity for which the orders are being placed.