What is Git?

Git is a version control system.

👉 In simple words: Git is used to save the history of changes in a project, like a “save game” in a video game.

Simple analogy

Imagine you are writing a paper in Word:

• Version 1

• Version 2

• Final version

• Final FINAL version 😅

Git does this automatically, but:

• Saves every change

• Lets you go back

• Lets you work as a team without stepping on each other

• Works perfectly with code

🧠 Why is Git so important?

Learning Git lets you:

• Never lose your work

• Work with other people

• Try ideas without breaking anything

• Work like a professional programmer

💡 ALL tech companies use Git.

🧩 Key concepts (very important)

Before using any commands, you need to understand these key concepts:

1️⃣ Repository (repo)

It’s the project.

📦 Think of a repository as:

A special folder that Git controls

It can contain:

• Code

• Images

• Documentation

• Any file

2️⃣ File

These are normal files:

• .html

• .css

• .js

• .txt

Git watches these files and detects changes.

3️⃣ Version / Commit

A commit is a snapshot of the project at a point in time.

📸 Every commit:

• Has a message (“what I did”)

• Has a date

• Has an author

Example of commit message:

Add login button

4️⃣ History

Git saves every commit in order.

This lets you:

• See what changed

• Go back to a previous version

• Know who did what

🧰 Installing Git

On Windows

Download from: 👉 https://git-scm.com

Install it with default options.

On macOS

brew install git

On Linux

sudo apt install git

Verify it is installed:

git --version

🚀 Getting started with Git (first steps)

Step 1: Create a project

Create a folder:

my-project

Enter the folder:

cd my-project

Step 2: Initialize Git

Inside the folder:

git init

👉 This creates a Git repository.

💡 Git now controls this folder.

📂 Git status (very important)

You can always ask:

git status

This tells you:

• Which files changed

• What is ready to save

• What is not

📝 Create your first file

Create a file called:

hello.txt

Content:

Hi, this is my first project with Git

Check status:

git status

You will see something like:

new untracked file

➕ Adding files (staging)

Git works in 3 areas:

1️⃣ Working Directory

Your normal files

2️⃣ Staging Area

Files ready to be saved

3️⃣ Repository

Saved files (commits)

To move a file to staging:

git add hello.txt

Or all of them:

git add .

💾 Save changes (commit)

Now save the changes:

git commit -m "Add hello.txt file"

🎉 First commit done!

🔁 Basic Git workflow (memorize it)

This is the most important Git workflow:

Edit → git add → git commit

It is always like that.

🧪 Modify a file

Edit hello.txt:

Hello world
I am learning Git

Check status:

git status

Add and save:

git add .
git commit -m "Update greeting message"

⏪ Go back in time

See history:

git log

You will see a list of commits.

Each commit has an ID.

To go back to a commit:

git checkout COMMIT_ID

⚠️ This is read-only mode (not for working).

🌿 Branches

What is a branch?

A branch is a parallel line of work.

🌱 It lets you:

• Try ideas

• Not break the main project

The main branch is called:

main

Create a branch

git branch new-feature

Switch to it:

git checkout new-feature

Or in a single step:

git checkout -b new-feature

Merge branches

Go back to main:

git checkout main

Merge:

git merge new-feature

🌍 Git vs GitHub (very important)

🚫 Git is NOT GitHub

GitHub uses Git, but they are not the same.

☁️ Upload a project to GitHub (basics)

1. Create a repository on GitHub

2. Connect the local repository:

git remote add origin URL

3. Push the code:

git push -u origin main

📥 Download a project

git clone REPO_URL

⚠️ Common mistakes

❌ Not committing often ❌ Bad commit messages ❌ Working without branches ❌ Not using git status

🧠 What to learn next

Once you master this:

1. .gitignore

2. Merge conflicts

3. Rebase

4. GitHub Flow

5. Pull Requests

📌 Final recap

Git lets you:

• Save versions

• Go back

• Work as a team

• Code professionally

Key workflow:

git status
git add .
git commit -m "clear message"