[simpaticoder]

Conceptually, I've come to think of containers as a kind of "known-good starting point", the origin of a coordinate system where "movement" is adding things. A set of Dockerfiles form a trie where each line of the Dockerfile is a node in that trie's branch. The great benefit of containers is that they allow you to reach any possible point in the space for a single process, without affecting any other. The other features of containers are, to me, secondary, things like container images, or even access or resource control. The main draw of the tool is giving the user a declarative way to move reliably and repeatedly through system-space, and to do so for any number of processes. (The main cost is the ~20% overhead such a system incurs).