A function is a block of reusable, organized code that is useful for performing a single action multiple times. Functions make it pretty easy to increase modularity and reuse the code and make it easy to maintain the application code. Python allows the users to create different functions along with the availability of different built-in functions like print(), ascii(), and many more. There are four types of Python functions: 1. No return and no argument value of the function 2. Function with a return value but no arguments 3. Function with no return value but an argument 4. Function with both return value and arguments