Git: A Comprehensive Guide for Developers

Git is the most widely used version control system, yet many developers only learn a handful of commands. This guide goes from the core model to advanced workflows so you can use Git with confidence rather than fear.

1. The core model

• **Commit** — a snapshot of your files with a parent pointer.
• **Branch** — a lightweight movable pointer to a commit.
• **HEAD** — where you currently are.
• **Index/Staging** — what will go into the next commit.

bash
git init
git add -p          # stage hunks interactively
git commit -m "message"

2. Branching and merging

Branches are cheap. Use one per feature:

bash
git switch -c feature/login
# ... work ...
git switch main
git merge feature/login

A fast-forward merge just moves the pointer; a merge commit records that two histories joined.

3. Rebasing

Rebase replays your commits onto another base, producing a linear history.

bash
git fetch origin
git rebase origin/main

Rule of thumb: rebase local commits; never rebase commits others have pulled.

4. Cherry-picking

Apply a single commit from another branch:

bash
git cherry-pick a1b2c3d

Useful for hotfixes you want in multiple branches without a full merge.

5. Merge conflicts

When Git can't auto-combine, it marks the file. Resolve, stage, and continue (see the dedicated merge-conflicts guide). The key is to understand both sides before choosing.

6. Keeping history clean

• One logical change per commit.
• Write messages that explain *why*, not just *what*.
• Use `git commit --amend` and interactive rebase to tidy before sharing:

bash
git rebase -i HEAD~5

7. Hooks for automation

Hooks run on events. A pre-commit hook can lint and format so bad code never enters history:

bash
# .git/hooks/pre-commit
npm run lint && npm run format

Or use Husky + lint-staged for a managed setup.

8. Pull requests and collaboration

• Push a branch and open a PR.
• Keep PRs small and focused for fast review.
• Use branch protection (required reviews, passing CI).

Quick reference

Task	Command
New branch	git switch -c name
See status	git status
Stage part	git add -p
Linearize	git rebase
Copy commit	git cherry-pick
Undo commit	git revert

Mastering Git isn't about memorizing commands — it's about understanding that commits form a graph you can reshape. Once that clicks, every workflow becomes a tool, not a mystery.