Git

You might say

AI broke my code. I want to get back to the last version that worked.

Keep a history of code changes so work can be compared and restoredGit records snapshots of a project and lets people compare changes, create independent branches, and combine work. Each developer has a full local history. GitHub and similar services host repositories and collaboration, but they are not Git itself.

Know first

Terminal

Files changedThese edits are not committed yet

Create a commitcommit→

✓Homepage update committedThe snapshot is now in local history

Upload commitspush→

GitHubThe remote repository now has the commit

Git tracks commits; GitHub hosts the remote repository

Commit a coherent set of changes to local history, then push those commits when you want to share or back them up on GitHub. Uncommitted edits are not included in a push.

When to use it

Save meaningful code changes
Compare the current work with an earlier state
Develop separate ideas on branches
Collaborate through a shared remote repository

When NOT to use it

Commit passwords, tokens, or environment secrets
Treat Git as a backup for generated files and large binaries
Combine unrelated changes in one unclear commit
Run unfamiliar destructive commands without checking the target

Anatomy

💻 Working tree Files you are editing git add → 📥 Staging areaChanges selected for the next commit git commit → 🗄 Local repository Your commit history git push → ☁️ Remote repository GitHub

Files changed in your working tree that are not yet committed

git add stages selected changes for the next commit; it does not move the file itself.

git commit records the staged changes as a new commit in local history.

git push publishes local commits to a remote repository so collaborators can fetch them.

Typical use cases

Feature development

Commits · main

Fix mobile navigation alignment

10 minutes ago

c7d8e9f

Build homepage layout

2 hours ago

a1b2c3d

Initialize project

3 days ago

0f1e2d3

Bug fix

zsh — my-first-page

$ git log --oneline c7d8e9f Fix mobile navigation alignment a1b2c3d Build homepage layout 0f1e2d3 Initialize project Each line shows a commit ID followed by its message

Team collaboration

zsh — my-first-page

$ git revert c7d8e9f [main f4e5d6c] Revert "Fix mobile navigation alignment" Creates a new commit that reverses the selected commit without deleting history

Release history

my-first-page

📄 index.htmlBuild homepage layout2 hours ago

📄 README.mdInitialize project3 days ago

📄 .gitignoreInitialize project3 days ago