Submodules vs Subtrees in Git

Created: 2020-09-03T08:15:19+00:00

Submodule

A submodule is a pointer to another git repository.
The URL and SHA sum is kept in the parent repository.
Submodules use the `git submodule` command.
Submodules need special treatment; they are separate repos, and so must be checked out and updated with appropriate commands.

A subtree embeds another git repository entirely.
A subtree may mix the histories of two repositories or it may be squashed.
A squashed subtree holds only a single commit of the original repository.
Subtrees require the `git-subtree` scripts be installed to create or update, but not use.
A subtree is like any other file in the repo and needs no special treatment, aside from when created or updated.