How branches are just files with hashes in Git - Step-by-Step CLI Walkthrough

Introduction

Branches in Git are simple files that store the hash of the latest commit. This means a branch is just a pointer to a specific commit in the project history.

When you want to understand how Git tracks changes behind the scenes

When you need to debug branch-related issues by looking at Git internals

When you want to manually inspect or manipulate branch pointers

When you want to explain Git branching to someone new using simple concepts

When you want to see how Git stores branch information in the .git directory

Commands

Create a new Git repository named example-repo to start tracking files and commits.

Terminal

git init example-repo

Expected Output

Initialized empty Git repository in /path/to/example-repo/.git/

Change directory into the new repository to run Git commands inside it.

Terminal

cd example-repo

Expected Output

No output (command runs silently)

Create a new file named file.txt with the content 'Hello'.

Terminal

echo "Hello" > file.txt

Expected Output

No output (command runs silently)

Stage the new file so Git knows to include it in the next commit.

Terminal

git add file.txt

Expected Output

No output (command runs silently)

Create the first commit with the staged file and a message describing the change.

Terminal

git commit -m "Add file.txt with Hello"

Expected Output

[master (root-commit) abcdef1] Add file.txt with Hello

 1 file changed, 1 insertion(+)

 create mode 100644 file.txt

→

-m - Add a commit message inline

Show the content of the master branch file, which is the hash of the latest commit it points to.

Terminal

cat .git/refs/heads/master

Expected Output

abcdef1234567890abcdef1234567890abcdef12

Display the commit history in a short format to see the commit hash and message.

Terminal

git log --oneline

Expected Output

abcdef1 Add file.txt with Hello

→

--oneline - Show each commit in one line with short hash and message

Key Concept

If you remember nothing else from this pattern, remember: a Git branch is just a file storing the hash of the latest commit it points to.

Common Mistakes

Trying to edit branch files directly without understanding the hash format

Editing branch files incorrectly can corrupt the branch pointer and cause Git errors

Use Git commands like git branch or git reset to safely move branch pointers

Expecting branch files to contain commit messages or file contents

Branch files only store commit hashes, not the commit details or file data

Use git log or git show to view commit details instead

Summary

Initialize a Git repository and create a commit to have a branch pointer.

The branch is stored as a file in .git/refs/heads/ with the commit hash inside.

Use git log and cat on the branch file to see how the branch points to the latest commit.