Introduction to Version Control

In modern software development, working on code without version control is like writing a book without saving backups. You are bound to lose data or make breaking changes that you cannot undo.

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18.1.1 The File Versioning Nightmare

Have you ever saved a project file like this?

• app.py
• app_final.py
• app_final_fixed.py
• app_backup_june30.py

This is called manual versioning, and it becomes a massive mess. If a bug is introduced, finding which version introduced it is a nightmare. Version Control Systems (VCS) solve this problem by tracking changes to your files systematically.

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18.1.2 What is Git?

Git is a local software tool that runs on your computer. It takes "snapshots" of your project directory at points you choose.

• Every time you save a snapshot, Git records what lines of code were added, removed, or modified.
• You can roll back to any previous snapshot at any time, protecting you against accidental code damage.

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18.1.3 Git vs. GitHub (The Core Difference)

Beginners often confuse Git and GitHub. They are different tools:

Feature	Git	GitHub
What is it?	A local command-line software tool.	A cloud-based web hosting service.
Where does it run?	Locally on your computer.	On remote cloud servers.
Do you need internet?	No, runs offline.	Yes, requires an active connection.
Primary Use:	Tracks files and commits changes locally.	Backs up code online and facilitates collaboration.

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18.1.4 Installing Git

Check if Git is already installed on your system by opening your terminal and typing:

git --version

If it is not installed, follow the setup for your Operating System:

• Windows: Download the installer from git-scm.com. Run the setup, keeping all default configuration options.
• macOS: Open a terminal and run git --version. If it is missing, macOS will prompt you to install the Xcode Command Line Tools, which includes Git. Alternatively, if you use Homebrew, run:

  brew install git

• Linux (Ubuntu/Debian): Run:

  sudo apt update
  sudo apt install git

Configuring Git (First Time Only)

Set up your identifier name and email address so Git commits list you as the author:

git config --global user.name "Your Name"
git config --global user.email "your.email@example.com"