🪣 Git Repository

The Git Repository is usually found in the .git/ folder inside the root project folder:

.git/
├── HEAD                # 🧭 Current position
├── config              # ⚙️ Settings
├── hooks/              # 🪝 Event scripts
├── index               # 📋 Index
├── logs/               # 📜 History logs
├── objects/            # 💾 Database of all versions of files (compressed)
│   ├── 8d/
│   │   └── 629a6f...
│   └── ...
└── refs/
    ├── heads/          # 👉 Branches
    │   ├── main
    │   └── feature-x
    └── tags/           # 🏷️ Tags

👉 Branches

A branch is simply a file in .git/refs/heads/ that contains the commit hash it points to. For example:

# .git/refs/heads/main:
8d629a6ffc1e5e3a0346681bb7576bowc3e9a0f

🧭 HEAD

HEAD is the special pointer that registers which commit/branch you're currently on:

# .git/HEAD:
ref: refs/heads/main

This means you're on the main branch.

📋 Index

• .git/index contains references to changes you have staged for inclusion in the next commit.
• Whatever you stage is saved in .git/objects and referenced by hash in the index.
• 🔑 index $\leftrightarrow$ .git/index $\leftrightarrow$ Draft of the next commit you are working on.
• You can stage:
  • New files.
  • All changes in an already tracked file.
  • Only some of the changes within a file.
    • 🧩 A changed segment within a file is called a hunk.
• ✨ If you stage a new file, then delete it, you can still commit the file!

🌲 Staging Hunks

• Go to "File Status" tab.
• Double-click on a file to view its changes.
• Stage segments of changes with "Stage hunk" or "Stage this line".

📸 Commits

When you commit, Git:

• Creates a new commit object in .git/objects using .git/index.
• If we are at a branch, updates the current branch pointer to the new commit.
• 🔒 Commit objects are immutable: To make any changes to a commit, a new commit with a new hash must be created to replace the previous one.