A container registry is a storage service where you upload, version, and distribute container images. Registries make it easy for servers, clusters, or CI systems to pull the exact image required for deployment. Popular registries include Docker Hub, GitHub Container Registry, and cloud-native registries like Amazon ECR or Google Artifact Registry.
Why it matters
Registries act as a central source of truth for the images used across environments. They improve security by scanning images for vulnerabilities and support access controls to restrict who can push or pull images. Without registries, teams would struggle to share or automate deployments.
Examples
Pushing an image with docker push uploads it to a registry, where it can later be pulled using its tag. Registries are explained in the lesson Container Registries.