Image

Term: Image / Template (VM or Container)

Definition: A preconfigured disk or filesystem snapshot used as a base to create new VMs or containers quickly and consistently.

Context/Example: A “Ubuntu server base image” used to spin up dozens of identical web-server VMs, or a Docker) image pushed to a registry for deployments. Related Concepts:

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Immutable Image

Term: Immutable Image

Definition: An image that is not modified after deployment; if you need a change, you rebuild a new image instead of patching the running instance.

Context/Example: Containers are often treated as immutable: when you need a new version of the app, you build a new container image and redeploy, rather than SSH-ing in to edit things.

Related Concepts: