A call option is a contract that gives the holder the right, but not the obligation, to buy an underlying
asset at a specified price on or before a specified date. The call option buyer is known as the "option holder" and the call option seller is known as the "option writer".
The call option buyer pays a premium to the option writer in exchange for the right to buy the underlying asset. The premium is typically a small percentage of the value of the underlying asset.
The call option buyer can exercise the option at any time on or before the expiration date. If the underlying asset price is greater than the strike price, the option holder will exercise the option and buy the underlying asset at the strike price. If the underlying asset price is less than the strike price, the option holder will not exercise the option and will lose the premium they paid for the option.
Call options are used by investors to speculate on the future price of an underlying asset. They can also be used to hedge against risk. For example, an investor who owns shares in a company can buy a call option on those shares to protect themselves against a fall in the share price.