dan , 7 hours ago

Have you used Docker before?

You know how Docker images are read-only? Changes are layered on top, but the base image itself is read-only and all other files are stored in a volume outside the container. Containers are seen as ephemeral. When you upgrade to a new version of the image, the container is deleted and a new fresh one is created.

Imagine that but for the whole OS.

A related concept is an “atomic” OS, which means upgrades are atomic. Atomic in this context means that either the whole upgrade succeeds, or the whole upgrade fails. It can’t get stuck in a half upgraded state. If you’ve dealt with databases before, it’s a bit like database transactions.