In your first year of learning computer science, think of defining a function like naming a recipe.

A function is a special piece of code that you can use again and again to do a specific job.

Important Parts of a Function:

1. Function Name: This is what you call your function. For example, calculateArea.

2. Parameters: These are the values you give to the function to help it do its job. For example, in calculateArea(length, width), length and width are the parameters.

3. Return Value: This is what the function gives back after it has finished its job. For figuring out the area, you can return the result of length multiplied by width.

Here’s an Example:

def calculateArea(length, width):
    return length * width

In this example, if you use calculateArea(5, 10), it gives you back $50$. That’s the area of a rectangle!