What is a module in Python?

A module in Python is fundamentally a file that contains Python code, which can include functions, classes, and variables. This allows for code organization and reuse, enabling programmers to structure their programs in a manageable way. By using modules, developers can import the contents into their scripts, which means they can utilize the functionalities like functions or classes defined within that module without redefining them.

For instance, you might have a file named math_operations.py that contains several functions for mathematical calculations. You can then import this module into other Python files using the import statement, making it easy to access and use those functions across different projects.

The other options relate to concepts in Python but do not accurately define what a module is. While the execution of code, error handling, and data types are important in programming, they do not encapsulate the primary definition and functionality of a module in Python.