From Fedora Project Wiki

Fedora Modularity :: Building a modular Linux OS with multiple versions of components on different lifecycles.

Modularity (formerly, Modularization) is an ongoing initiative in Fedora to resolve the issue of divergent, occasionally conflicting lifecycles of different components. A module provides functionality (for instance a web server) and includes well-integrated and -tested components (for instance Apache httpd and the libraries on which it depends). It can be deployed into production in various ways, for instance as "classic" RPM packages or a container image, and is updated as a whole. Different modules can emphasize new features, stability, security, etc. differently.

Fedora Modularity