Git concepts: .git directory

The .git directory is a hidden folder in your project that Git uses to store all the information and metadata necessary for version control. It's essentially the repository's brain, where all the magic happens. Here's a breakdown of what you'll find inside:

HEAD: A reference to the last commit in the currently checked-out branch.

config: Contains project-specific configuration options.

description: Only used by the GitWeb program, usually contains a short description of the repository.

hooks: This is where your client or server-side hook scripts would be placed.

info: Contains the global excludes file.

objects: This directory stores all the data of your Git objects - commits, trees, blobs (file content), and tags.

refs: This directory has pointers to commits (basically, the ends of branches).

index: Represents the staging area.

logs: Records changes made in the refs subdirectories.

packed-refs: Stores references to branches and tags in a more disk-space-efficient way.

FETCH_HEAD: Keeps track of the branch which was checked out during the last git fetch execution.

ORIG_HEAD: Used by commands to store the previous state of HEAD at the time of their operation.

It's important to note that you should not change anything inside the .git directory manually. Git has commands for everything that needs to be done. Manipulating this directory directly could corrupt your repository.