Python Functions Explained: Parameters, Return Values, and Scope Basics

Python functions are reusable named blocks of code defined with the 'def' keyword and executed only when explicitly called. They can accept inputs through parameters, which may have default values or be passed by name using keyword arguments. When the number of inputs is unknown, '*args' and '**kwargs' allow functions to handle variable positional and keyword arguments respectively. The 'return' statement sends a computed value back to the caller for further use, unlike 'print()', which only displays output to the console without storing it. Understanding these core concepts — definition, parameters, return values, and variable scope — is fundamental to writing effective Python programs.