GIT

GIT Version Control System

✅ Core Essence of Git

At its heart, Git is a tool to track and manage changes to files over time, especially source code, and it enables multiple developers to collaborate without overwriting each other’s work.

Think of it like a time machine + collaboration manager for your code.

🔄 What Makes Git Special?

1. Distributed

Each user has a complete copy of the repository.
You can work offline.
Full access to history and no single point of failure.

2. Version Tracking

Each "commit" in Git saves:

What files changed
What was added/removed
Who made the change and when
A unique ID (SHA-1 hash) for the commit

This enables you to:

Go back to any previous version
Compare versions
Branch and experiment safely

3. Branches & Merging

Git makes it easy to:

Create a branch to work independently
Merge branches back into the main branch

This supports parallel development, feature testing, and bug fixes.

🧠 Think of Git Like This

git init: Start your project diary.
git add: Tell Git which files to track.
git commit: Take a snapshot of changes.
git branch: Start a new timeline of work.
git merge: Combine changes from different timelines.
git push/pull: Share and fetch changes with others.

🤝 Collaboration

Git enables teamwork via remote repositories like GitHub, GitLab, and Bitbucket. Collaborators can:

Push their changes to a shared hub
Pull updates from others
Review and approve changes (pull requests)
Resolve merge conflicts

🔁 Git Push, Pull Requests, and Forks

✅ git push

git push uploads your local commits to a remote repository (like GitHub).

Example:

git push origin main

This pushes your changes to the main branch on the remote named origin.

✅ Pull Request (PR)

A Pull Request is a request to merge your changes into someone else’s branch or repository. It's used in collaboration workflows for:

Code review
Discussion and feedback
CI checks (automated tests)
Approval and controlled merging

Workflow:

You push changes to your branch
Create a pull request on GitHub
Reviewers approve or suggest changes
The branch is merged after review

✅ Fork

A fork is a personal copy of someone else's repository on GitHub. It allows you to:

Experiment freely
Work independently without affecting the original
Submit a Pull Request later if needed

Typical Open Source Flow:

Fork the repo on GitHub
Clone it to your machine
Make changes and push to your fork
Create a pull request to the original repo

🧩 Other Git Concepts

✅ git status

Displays the current state of the working directory and staging area.

git status

✅ git log

Shows the project's commit history.

git log

Optional flags:

git log --oneline --graph --all

✅ git diff

Shows differences between files, commits, or branches.

git diff
git diff --staged
git diff HEAD~1

✅ git clone

Creates a local copy of a remote Git repository.

git clone https://github.com/user/repo.git

✅ git rebase

Rewrites the base of a branch by reapplying commits on a new base.

git rebase main

Note: Avoid using on public branches to prevent history conflicts.

✅ git stash

Temporarily saves changes that are not ready to be committed.

git stash
git stash apply
git stash pop
git stash list

✅ .gitignore

Used to tell Git to ignore specific files or directories.