Trading without stop loss, the same like gambling that you can loss 90% more.
Trading is already a gamble, but having a stop loss is the way that you can minimize the risk or cutting your losses to become lesser so that in your next trade, you have a possibility to take a huge profit. Stop loss is also one of the best ways for Risk Management, in trading, risk management's important tool is the stop loss. There are also some exchanges that have two kinds of stop-loss, the LIMIT and MARKET stop loss.
LIMIT Stop-loss - You have to manually set the price when you will close your position.
MARKET Stop-loss - This will automatically close your position, once the last price is hit, based on your input on stop loss.
In most exchange, the LIMIT stop-loss is only available. MARKET stop-loss is rarely used.