A Call option gives its buyer the right, but not the obligation, to buy the underlying asset at the strike price, by or on expiry. Buying a Call is a bullish position — it profits if the underlying’s price rises above the strike price by more than the premium paid.
Related Reading
See the full Call vs Put comparison, including all four basic Option positions, in Call Options vs Put Options: What’s the Difference?. Module 6 covers Call options in complete depth.