Calls and puts are the foundation of all options strategies, yet they are often misunderstood by newer traders. A call option gives the buyer the right to purchase an asset at a specific price, while a put option gives the right to sell. Each reacts differently depending on price movement, volatility, and time remaining until expiration. This section explains how calls and puts gain and lose value, when each is typically used, and why simply predicting market direction is not enough to ensure profitability.