Git doesn’t store changes the way traditional tools do — it uses a snapshot model: Every time we commit, Git takes a snapshot of the current state of the project. If certain files haven’t changed, Git doesn’t duplicate them — it references the previous version to save space.

• git add moves changes from the working directory to the staging area

• git commit captures the staged changes and writes them into the repository.

Git Diagram

Understanding the .git Folder

When we initialize a Git repository git init , Git automatically creates a hidden .git folder. This folder is the entire guts of your repository — without it, our project has no version history.

• objects/ ……… Stores all Git objects (blobs, trees, commits).

• refs/ ………….. Contains pointers to branches and tags.

• HEAD ……….. Points to your current branch.

• index ………… The staging area.

• config/ ……… Repository Settings.

• logs/ ………… Stores history of refrences updates

If you delete .git you lose your entire Git history

.git diagram

Git Objects: Blob, Tree, Commit

Blob — Binary Large Object

• Represents the contents of a file.

• Stores file data only — no filename or metadata.

Tree — Directory Snapshot

A tree object represents a directory — mapping filenames to blobs (files) or other trees (subdirectories)

Commit — Snapshot + History

Each commit snapshot creates a history chain of changes.

How Git Tracks Changes

Git tracks changes by creating new objects only when needed.

Working Directory ↓ git add Staging Area (Index) ↓ git commit Git Repository (.git)

git add

• Takes files from working directory

• Creates blob objects (if they changed)

• Updates the staging index

git commit

• Takes the staged snapshot

• Builds tree objects

• Creates a new commit object

• Updates HEAD to point to the new commit