Puts are options for if you think the markets are going down. It gives you the option to short the market, but only if the stock price is past your strike price you bought them for. Calls are the opposite for if you believe the markets are going up. There's also an added risk of degradation over time. You buy with an expiration date. Could be a day/week/months/years but the closer to your expiration, the quicker it can degrade your option value. So basically, you're betting a stock price is going to go up/down past a specific price by a certain date.