image-based OS
also: immutable OS, atomic OS, image-based distribution
An operating system where the entire system state—kernel, drivers, libraries, and applications—is packaged as a single immutable disk image that is deployed and updated atomically as a whole.
An image-based OS treats the entire operating system as a unified, versioned artifact rather than a collection of individually managed components. The system is built once, tested as a complete unit, and deployed as a single disk image. Updates replace the entire image atomically, rather than patching individual packages.
This approach contrasts with traditional package-based systems (like Fedora or Debian) where you install and update individual packages. Common examples include Fedora CoreOS, Flatpak runtimes, and container base images like those used in Docker.
Benefits include: improved reliability (tested as a unit), simplified rollbacks (revert to previous image), reduced attack surface (minimal unnecessary components), and consistent deployments across machines. The tradeoff is less granular control and potentially larger update sizes, though differential updates partially mitigate this.