What is the difference between straddles and strangles?

josephconlin answered 2 years ago …

A straddle is when you buy a put and a call at the same strike price and expiration date. You expect the stock to move strongly, but you don't know which way it will go. It closely mirrors just buying the underlying stock.

A strangle is when you buy an out of the money call and an out of the money put with the same expiration on the same underlying stock. You expect the stock to move strongly, but you don't know which way it will go. You pay less for the options, but the stock needs to move farther to make the option in that direction more valuable.

See the following links:
http://www.investopedia.com/terms/s/straddle.asp
http://www.investopedia.com/terms/s/strangle.asp