Python modules are files containing reusable code, such as functions, classes, or variables, which help organize and structure programs efficiently. Built-in modules like math or datetime offer ready-to-use functionality, while user-defined modules allow custom code reuse. To import a module, use the import keyword (e.g., import math) or from modulename import functionname to import specific components. Modules promote clean code, reduce redundancy, and make debugging easier. Mastering how to use and create modules is essential for any developer working with Python. If you want to boost your skills, consider enrolling in a Python certification course.