In Python, a function is a reusable block of code that performs a specific task or set of tasks. Functions help in organizing code into modular units, making it more readable, maintainable, and reusable. They play a crucial role in structuring programs and promoting the concept of code reusability.

Here is the basic syntax of a function in Python:

def function_name(parameters):
    # code block
    # ...
    return result  # optional

• def: This keyword is used to define a function.
• function_name: It is the identifier for the function, by which you can call and reference it.
• parameters: These are variables that the function can accept as input (optional).
• code block: This is the set of instructions or statements that the function executes when called.
• return: This keyword is used to specify the value that the function should return (optional).

Here's a simple example of a function that adds two numbers:

def add_numbers(a, b):
    result = a + b
    return result

# Calling the function
sum_result = add_numbers(3, 4)
print(sum_result)  # Output: 7

In this example, add_numbers is the function name, and it takes two parameters (a and b). Inside the function, it calculates the sum of a and b and returns the result. The function is then called with arguments 3 and 4, and the result is printed.

Functions can have various use cases, and they are a fundamental building block in Python programming. They can be defined with or without parameters, and they can return values or perform tasks without returning anything.

Thank you.