OCI: Container Standards¶
The Open Container Initiative (OCI) defines open specifications so an image created by one compatible tool can be used by another compatible runtime or registry.
| Specification | Defines |
|---|---|
| Image Specification | image manifests, configuration, layers, and layout |
| Runtime Specification | runtime bundle and how a runtime starts the process |
| Distribution Specification | registry API behavior for pushing and pulling content |
Application → OCI image → registry → image layers + config
→ runtime bundle → OCI runtime → isolated process
An OCI image is a portable artifact: metadata plus content-addressed filesystem layers. A runtime bundle is a prepared root filesystem and configuration handed to an OCI runtime. The image is not running; the runtime creates a container process from it.
Interoperability does not mean every feature is identical. A tool's build cache, GUI, networking implementation, policy controls, and extensions may differ. It does mean OCI-compatible images can move across compatible ecosystems instead of being tied to one vendor's image format.