The premium is the price paid to buy an option (call or put), or the amount collected when selling one. It represents the cost for the rights granted by the option contract.
One standard options contract represents 100 shares. So, if a call option has a premium of $2, the buyer pays $2 × 100 = $200.
The premium is influenced by both intrinsic value (if the option is in-the-money) and extrinsic value (time until expiration, volatility, etc.).