CALL : If you buy a CALL ( or you sell a PUT) of particular script means you are bullish on script. If scripts moves up you make money.
PUT : If you buy a PUT ( or you sell a CALL) of a particular script means you are bearish on script. If script goes down you make money.

Buy CALL / PUT : loss limited & profit unlimited.
Sell CALL / PUT : profit limited & loss unlimited.

Hope this clears your doubts.