Options are different types of products design to take advantage of market volatility based on news.  There are two fundamental products of options - CALL and PUT.

Typically, buying CALL are used as part of bullish strategies and buying PUT are being used for bearish strategies.  Timing is very critical for these types of trades.  The inverse is selling of those options.

CALL: When you sell these products against the stocks you own, is called covered CALL. If you sell them without owning that stock, it is called naked CALL.  

PUT:  When you sell these product naked you are taking unlimited downside risk. This may be a good strategy if you are bullish about that security.

You need to be very careful when selling anything naked.