distribution/docs/glossary.md

Glossary

This page contains distribution related terms. For a complete Docker glossary, see the glossary in the full documentation set.

Blob

The primary unit of registry storage. A string of bytes identified by content-address, known as a _digest_.

<dt>Image</dt>
<dd>An image is a collection of content from which a docker container can be created.</dd>

<dt>Layer</dt>
<dd>
A tar file representing the partial content of a filesystem. Several
layers can be "stacked" to make up the root filesystem.
</dd>

<dt>Manifest</dt>
<dd>Describes a collection layers that make up an image.</dd>

<dt>Registry</dt>
<dd>A registry is a service which serves repositories.</dd>

<dt>Repository</dt>
<dd>
A repository is a collection of docker images, made up of manifests, tags
and layers. The base unit of these components are blobs.
</dd>

<dt>Tag</dt>
<dd>Tag provides a common name to an image.</dd>

<dt>Namespace</dt>
<dd>A namespace is a collection of repositories with a common name prefix. The
namespace with an empty common prefix is considered the Global Namespace.</dd>

<dt>Scope</dt>
<dd>A common repository name prefix.</dd>