A Stop-Limit order will be executed at a specified (or potentially better) price after a pre-set stop price has been reached. Once the stop price is reached, the Stop-Limit order turns into a Limit order to buy or sell at the limit price or better.
Example: The latest traded price of ETH/DAI is 180 DAI while the resistance is around 184 DAI. In case you believe that ETH will go higher and break the resistance level, you can set a Stop-Limit order that that will automatically trigger once the resistance level is reached. Hence, you set a Stop Rate at 185 DAI and the Limit at 187 DAI.