Modularity is the initiative to disconnect the lifecycle of applications from each other and from the lifecycle of the operating system, while still maintaining the ease of use of a typical Linux distribution. This work has produced two changes that have been incorporated into Fedora 27: Host and Platform and Modular Server.
The Host and Platform change is an evolution of the Base Runtime module concept that was introduced in the Fedora 26 Boltron Release, splitting the minimal system further into independent modules, which gives greater flexibility when composing and maintaining the base system.
The Host module delivers hardware enablement components such as the kernel, bootloaders, firmware, possibly additional device drivers and other components closely linked to these.
The Platform module defines the operating system release and includes various base userspace components ranging from the C library and init system to system management & deployment tools, container runtime and possibly several services that are commonly considered to be part of the base system experience.
The Host and Platform modules are independent, making it possible to run the same Host with different Platforms and vice versa. Each of the two modules has its own life cycle, update cadence and versioning scheme.
The Modular Server change promotes the work done in the Fedora 26 Boltron Release to the Fedora Server Edition. In Fedora 27, the Fedora Server Edition is created and delivered using the Modularity infrastructure pipeline and the Host and Platform design concept.
Other Fedora Editions and Spins will not change in this release; users who want to use Fedora to create a server (as opposed to capital-S Fedora Server) without Modularity can use one of the other editions, for example the Fedora Cloud Base Image, or the "Everything" network installer.