On November 20, Binance, a cryptocurrency exchange based in Tokyo, has made an announcement stating that a function of Stop-Limit was implemented. Basically, it means that a stop-limit order will be executed at a certain and potentially better price, after a given stop price has been reached. When the stop price is reached, the stop-limit order becomes a limit order to buy or sell at the limit price or better.
— binance (@binance_2017) 11 December 2017
The Stop-Limit function was added so that the users will not have to continuously watch market movements waiting for the price to reach the target price they are expecting.
To show an Example: The last traded price of BNB is 0.000165 BTC, and the resistance is around 0.000169 BTC. If you think that the price will go higher after the price reaches the resistance, you can put a Stop-Limit order to automatically buy more BNB at the price of 0.000170 BTC.
Binance official statement