Grouping source files and exports refers to organizing your codebase by logically bundling related files and their public interfaces (exports). This involves structuring directories and files to represent features, components, or modules, and using language-specific mechanisms to explicitly declare which functions, classes, or variables are accessible externally from those bundles. This differs from scattering files randomly or exposing every element globally, promoting controlled access and clarity.

This practice is fundamental across programming. In web development using React, related component files (e.g., Button.js, Button.css, Button.test.js) are grouped into a Button directory, and the main Button.js file exports the component as the public API. In Python, files within a directory become a package, and the __init__.py file can define which sub-modules or functions are exported when the package is imported.

Good grouping enhances code discoverability, reuse, and reduces naming conflicts by restricting exports. However, poorly designed groups (too broad or too granular) or inconsistent export patterns can create confusion and maintenance overhead. Thoughtful grouping facilitates modular design, enabling teams to collaborate effectively and scale applications by understanding dependencies through clear boundaries, driving innovation through composable units.