A function call is a way to execute a specific block of code, known as a function, within a program. When a function is called, the program temporarily pauses its current task, jumps to the function, runs the code inside it, and then returns to where it left off. This helps organize code and makes it reusable, allowing the same function to be called multiple times with different inputs. In programming, functions can take inputs, called parameters, and return outputs. For example, a function named add might take two numbers as parameters, add them together, and return the result. This modular approach simplifies complex tasks and enhances code readability.