A limit order tells the exchange the maximum price you will pay to buy, or the minimum you will accept to sell. It goes into the order book and executes only when a matching price is available. If SBI is quoting ₹800.10 and you place a limit buy at ₹799, nothing happens until a seller is willing to sell at ₹799 or lower. The benefit is control: you never pay more than planned and never suffer a bad fill in a thin stock. The cost is that the order may never execute and you may miss the move. Limit orders are the sensible default for delivery investing and for any stock with a wide spread. For fast exits, especially when a stop loss triggers, a limit price set too tight can leave you stuck in a falling position, so leave some room.