Purchasing a call option is essentially betting that the price of the share of security (like a stock or index) will go up over the course of a predetermined amount of time. For instance, if you buy a call option for Alphabet (GOOG) at, say, $1,500 and are feeling bullish about the stock, you are predicting that the share price for Alphabet will increase. 
However, options are not the same thing as stocks because they do not represent ownership in a company. And, although futures use contracts just like options do, options are considered lower risk due to the fact that you can withdraw (or walk away from) an options contract at any point. The price of the option (its premium) is thus a percentage of the underlying asset or security.