📝 Add Git’s data and storage model

Author: veit

docs/productive/git/advanced/internals.rst

@@ -2,12 +2,81 @@
 ..
 .. SPDX-License-Identifier: BSD-3-Clause
 
-Git’s database internals
-------------------------
+Git Internals
+=============
+
+So far, we have looked at how you can use Git to manage the different states of
+your code. Now we want to show you the :ref:`data <git-data-model>` and
+:ref:`storage models <git-storage-model>` that underlie Git.
+
+Data Model
+----------
+
+You will be able to use Git more effectively once you understand the data model.
+Git manages four types of data:
+
+Objects
+~~~~~~~
+
+.. include:: ../glossary.rst
+   :start-after: start-object
+   :end-before: end-object
+
+Commit
+::::::
+
+.. include:: ../glossary.rst
+   :start-after: start-commit
+   :end-before: end-commit
+
+Tree
+::::
+
+.. include:: ../glossary.rst
+   :start-after: start-tree
+   :end-before: end-tree
+
+Blob
+::::
+
+.. include:: ../glossary.rst
+   :start-after: start-blob
+   :end-before: end-blob
+
+Tag
+:::
+
+.. include:: ../glossary.rst
+   :start-after: start-tag
+   :end-before: end-tag
+
+References
+~~~~~~~~~~
+
+.. include:: ../glossary.rst
+   :start-after: start-refs
+   :end-before: end-refs
+
+Index
+~~~~~
+
+.. include:: ../glossary.rst
+   :start-after: start-index
+   :end-before: end-index
+
+Reflog
+~~~~~~
+
+.. include:: ../glossary.rst
+   :start-after: start-reflog
+   :end-before: end-reflog
+
+.. _git-storage-model:
+
+Storage model
+-------------
 
 .. seealso::
-   * `Commits are snapshots, not diffs
-     <https://github.blog/open-source/git/commits-are-snapshots-not-diffs/>`_
    * Git’s database internals
 
      * `Part I: packed object store
@@ -20,3 +89,10 @@ Git’s database internals
        <https://github.blog/open-source/git/gits-database-internals-iv-distributed-synchronization/>`_
      * `Part V: scalability
        <https://github.blog/open-source/git/gits-database-internals-v-scalability/>`_
+
+Packfiles
+~~~~~~~~~
+
+.. include:: ../glossary.rst
+   :start-after: start-packfile
+   :end-before: end-packfile

docs/productive/git/branch.rst

@@ -302,6 +302,8 @@ Delete branches
    * `Git Branching - Branches in a Nutshell
      <https://git-scm.com/book/en/v2/Git-Branching-Branches-in-a-Nutshell>`_
 
+.. _remote-branches:
+
 Remote branches
 ---------------