What is the purpose of the def function in Python?

In Python, the def function is used to define a function. A function is a reusable code block that can be used to perform specific tasks or calculations. By using the def keyword, you can define a function in a program and give it a name and a set of parameters. When a program needs to perform a specific operation, it can call that function and pass the necessary parameters. Functions can take input parameters and return output results. By defining functions, the readability, reusability, and maintainability of the code can be improved.