Options are a type of contract that gives the buyer the right to buy or sell a security at a specified price at some point in the future. An option holder is essentially paying a premium for the right to buy or sell the security within a certain time frame.
Or as it's conveniently named, 1 Long put closer to the money, 1 short put further from the money, and 2 more short puts even further from the money. Preferably, as far away as possible while maintaining a net credit for the trade.