The fixed stop does not change with price. But the trailing stop loss will change with price. For example, a trader bought Nifty future at 10800 and he keeps 20 points stop at 10780. Now he decides to raise his stop loss by 10 points, with every 10 points up-move of price. So when the price reaches 10810 the stop moves to 10790. Similarly, when the price moves to 10820, the stop moves to 10800 and so on. If the trailing stop gets hit, that marks an exit from the buy position. This trailing stop loss system has been incorporated in Zerodha bracket orders.