A Put Bear Spread is buying a put option while selling a put option with a lower strike price. Both options are in the same expiration month.
The Max Loss is limited to the net amount paid for the spread. I.e. the premium paid for the long put less the premium received for the short put.
The Max Gain is limited to the difference between the two strike prices minus the net premium paid for the position.
When to use: When you are bearish on market direction.
A Put Bear Spread has the same payoff as the Call Bear Spread as both strategies hope for a decrease in market prices. The main difference between the two is that the put spread version is a debit spread (you pay money to put the trade on) whereas the call version is a credit spread (you receive the premium up front).