Some notes about the contents of the .git directory that resides in the root of a git repository.

• config file: contains project-specific configurations
• info/exclude file: ignore patterns in addition to .gitignore files but not tracked
• hooks directory: client- or server-side hook scripts
• HEAD file: points to the currently checked out branch
• objects directory: stores the content of the git database
• refs directory: stores pointers to commit objects (branches)
• index file: staging area information
• description file: only used by the GitWeb program

For submodules the directory is in the .git directory of the main repository (“supermodule”).

The .git directory of a repository can be shown with git rev-parse --git-dir