> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Image Addressing Convention
> This article explains how Docker interprets image names, helping avoid naming conflicts and ensuring correct image retrieval from registries.
In this lesson, you’ll learn how Docker interprets image names when you pull or reference them. Understanding these conventions helps you avoid naming conflicts and ensures you’re pulling or pushing images to the correct registry.
## Pulling an Image
For example, running:
```bash theme={null}
docker image pull httpd
```
might look simple—but what does `httpd` actually represent, and where does Docker retrieve it from?
## Docker Image Naming Components
A complete Docker image reference can include up to three parts:
| Component | Description | Example |
| ---------- | ------------------------------------------------- | ------------------------------- |
| Registry | Hostname of the registry (defaults to Docker Hub) | `docker.io` |
| Namespace | User or organization under which the image lives | `library` (for official images) |
| Repository | Name of the image project | `httpd` |
### Implicit Namespace
When you specify only `httpd`, Docker assumes you want the official image from Docker Hub’s **library** namespace.\
Effectively, Docker interprets:
```yaml theme={null}
image: library/httpd
```
Here, `library` is the namespace for curated, official images on Docker Hub, and `httpd` is the repository name.
### Default Registry
By default, Docker pulls from Docker Hub (`docker.io`). Omitting the registry is shorthand for:
```yaml theme={null}
image: docker.io/library/httpd
```
The registry is where images are stored. When you build and push an image, it goes to this registry; when you pull, it comes from here.
You can verify the full reference of an existing image with:
```bash theme={null}
docker image inspect httpd --format '{{.RepoDigests}}'
```
## Referencing Other Registries
If your image lives in a different registry—such as Google Container Registry or a private registry—you must prepend the registry hostname:
```yaml theme={null}
# Google Container Registry (GCR)
image: gcr.io/your-project/httpd
# Private registry
image: registry.example.com/your-namespace/httpd
```
Before interacting with private registries, authenticate using:
```bash theme={null}
docker login
```
Always ensure you’re logged in to the correct registry. Pushing to the wrong registry can overwrite critical images.
***
## Links and References
* [Docker Image Overview](https://docs.docker.com/engine/reference/commandline/image/)
* [Docker Hub Documentation](https://docs.docker.com/docker-hub/)
* [Google Container Registry](https://cloud.google.com/container-registry)