Git & GitHub

Introduction to GitHub

13 min Lesson 18 of 35

Introduction to GitHub

GitHub is the world's largest platform for hosting and collaborating on Git repositories. While Git is the version control system that runs on your computer, GitHub is a cloud-based hosting service that brings social coding, collaboration tools, and project management to your Git workflows.

What is GitHub?

GitHub is much more than just a place to store code:

GitHub provides:
- Remote Git repository hosting
- Web-based Git repository visualization
- Collaboration tools (pull requests, code review)
- Project management (issues, projects, milestones)
- Documentation hosting (wikis, README files)
- Continuous integration/deployment (GitHub Actions)
- Package registry (npm, Docker, Maven, etc.)
- Security features (Dependabot, code scanning)
- Community features (stars, forks, discussions)

Fun Fact: GitHub hosts over 100 million repositories and has more than 90 million developers worldwide. It was acquired by Microsoft in 2018 for $7.5 billion.

GitHub vs Git: Understanding the Difference

Many beginners confuse Git and GitHub. Here's how they differ:

Git:
- Version control system (software)
- Runs locally on your computer
- Command-line tool
- Created by Linus Torvalds (2005)
- Free and open source
- Works without internet

GitHub:
- Web-based hosting service for Git
- Runs on GitHub's servers (cloud)
- Web interface + Git commands
- Founded by Tom Preston-Werner (2008)
- Free tier + paid plans
- Requires internet connection

Analogy: Think of Git as Microsoft Word (software that creates documents) and GitHub as Google Drive (service that stores and shares those documents online).

Why Use GitHub?

GitHub offers numerous benefits for individual developers and teams:

For Individual Developers:
✓ Portfolio showcase for potential employers
✓ Backup of your code in the cloud
✓ Learn from millions of open source projects
✓ Contribute to open source software
✓ Build a professional reputation

For Teams:
✓ Centralized code repository
✓ Built-in code review process
✓ Issue tracking and project management
✓ Automated workflows with Actions
✓ Team collaboration tools
✓ Access control and permissions

Creating a GitHub Account

Getting started with GitHub is straightforward:

Steps to create an account:

1. Visit https://github.com
2. Click "Sign up" in the top right
3. Enter your email address
4. Create a password (use a strong one!)
5. Choose a username (this will be public)
6. Verify you're not a robot
7. Check your email for verification code
8. Complete your profile (optional but recommended)

Username Tips:
- Use a professional username (employers will see it)
- Keep it simple and memorable
- Match other professional profiles (LinkedIn, etc.)
- Examples: john-smith, jsmith-dev, johnsmith

Pro Tip: Your GitHub username becomes part of your repository URLs (github.com/username/repo), so choose wisely. You can change it later, but it may break links.

GitHub Pricing and Plans

GitHub offers different plans for various needs:

GitHub Free:
- Unlimited public repositories
- Unlimited private repositories
- 2,000 Actions minutes/month
- 500 MB package storage
- Community support
- Perfect for individuals and small teams

GitHub Pro ($4/month):
- Everything in Free
- 3,000 Actions minutes/month
- 2 GB package storage
- Advanced tools and insights
- Pages and Wikis for private repos

GitHub Team ($4/user/month):
- Everything in Pro
- Team access controls
- Multiple reviewers in pull requests
- Draft pull requests

GitHub Enterprise:
- Self-hosted or cloud
- Advanced security features
- Compliance certifications
- Dedicated support

Note: Most developers start with the free plan, which is more than sufficient for learning, personal projects, and even professional work.

Setting Up SSH Keys

SSH keys provide a secure way to authenticate with GitHub without entering passwords:

1. Check for existing SSH keys:
ls -al ~/.ssh
# Look for id_rsa.pub or id_ed25519.pub

2. Generate new SSH key (if needed):
ssh-keygen -t ed25519 -C "your_email@example.com"

# For older systems:
ssh-keygen -t rsa -b 4096 -C "your_email@example.com"

3. Start SSH agent:
eval "$(ssh-agent -s)"

4. Add SSH key to agent:
ssh-add ~/.ssh/id_ed25519

5. Copy public key to clipboard:
# macOS:
pbcopy < ~/.ssh/id_ed25519.pub

# Linux:
cat ~/.ssh/id_ed25519.pub
# Then manually copy the output

# Windows (Git Bash):
clip < ~/.ssh/id_ed25519.pub

Add SSH key to GitHub:

Go to GitHub.com and log in
Click your profile photo → Settings
Click "SSH and GPG keys" in sidebar
Click "New SSH key"
Give it a title (e.g., "My Laptop")
Paste your public key
Click "Add SSH key"

Test SSH connection:
ssh -T git@github.com

# Success message:
Hi username! You've successfully authenticated...

Personal Access Tokens (PAT)

Personal Access Tokens are an alternative to SSH for HTTPS authentication:

When to use PATs:
- Authenticating with HTTPS instead of SSH
- Using GitHub API
- Accessing GitHub from scripts/tools
- When SSH is blocked by firewall

Creating a Personal Access Token:

1. GitHub.com → Settings → Developer settings
2. Click "Personal access tokens" → "Tokens (classic)"
3. Click "Generate new token" → "Generate new token (classic)"
4. Give token a descriptive name
5. Set expiration (30/60/90 days or custom)
6. Select scopes (permissions):
   - repo: Full control of private repositories
   - workflow: Update GitHub Actions workflows
   - admin:org: Manage organization
7. Click "Generate token"
8. Copy token immediately (you won't see it again!)

Using the token:
# When prompted for password, use token instead
git clone https://github.com/username/repo.git
Username: your_username
Password: paste_your_token_here

Security Warning: Treat Personal Access Tokens like passwords. Never commit them to repositories or share them. Store them securely (password manager recommended).

Enabling Two-Factor Authentication (2FA)

2FA adds an extra layer of security to your GitHub account:

Setting up 2FA:

1. GitHub.com → Settings → Password and authentication
2. Click "Enable two-factor authentication"
3. Choose authentication method:
   - Authenticator app (recommended)
   - SMS text messages

Using an authenticator app:
1. Download an app (Authy, Google Authenticator, 1Password)
2. Scan QR code with the app
3. Enter 6-digit code to verify
4. Save recovery codes in a safe place!

Important notes:
- Save recovery codes! (Print or password manager)
- You'll need 2FA code each time you log in
- PATs still work with 2FA enabled
- Some Git operations require PAT instead of password

Best Practice: Enable 2FA immediately after creating your account. It significantly increases account security and is required for many organizations.

Configuring Git for GitHub

Configure Git with your GitHub account information:

# Set your name (use your GitHub name)
git config --global user.name "Your Name"

# Set your email (use your GitHub email)
git config --global user.email "your_email@example.com"

# Set default branch name to main
git config --global init.defaultBranch main

# Set default editor
git config --global core.editor "code --wait"  # VS Code
git config --global core.editor "vim"          # Vim

# Verify configuration
git config --list

GitHub Ecosystem and Alternatives

While GitHub is the most popular, there are alternatives:

GitHub:
- Most popular (100M+ repos)
- Best for open source
- Excellent community features
- Owned by Microsoft

GitLab:
- Strong DevOps features
- Built-in CI/CD
- Self-hosting option
- Popular in enterprises

Bitbucket:
- Atlassian ecosystem (Jira integration)
- Good for private repositories
- Popular in corporate environments

Other platforms:
- Gitea (self-hosted, lightweight)
- SourceForge (legacy platform)
- Azure DevOps (Microsoft enterprise)

GitHub Desktop and CLI

GitHub provides additional tools beyond the web interface:

GitHub Desktop:
- Visual Git client
- Simplifies Git operations
- Great for beginners
- Available for Windows and macOS
- Download: desktop.github.com

GitHub CLI (gh):
- Command-line tool for GitHub
- Manage repos, issues, PRs from terminal
- Install: cli.github.com

# Example GitHub CLI commands:
gh repo create my-project --public
gh issue list
gh pr create --title "Add feature"
gh pr merge 123

Getting Started Exercise:

Set up your GitHub account:

Create a GitHub account (if you don't have one)
Complete your profile with a bio and profile picture
Generate SSH keys and add to GitHub
Test SSH connection with ssh -T git@github.com
Enable two-factor authentication
Configure Git with your GitHub name and email
Explore trending repositories on GitHub
Star an interesting repository

Bonus: Install GitHub Desktop or GitHub CLI and explore its features.

Summary

In this lesson, you learned:

GitHub is a cloud hosting service for Git repositories with collaboration tools
Git is the version control software; GitHub is the hosting platform
GitHub offers free plans suitable for most developers
SSH keys and Personal Access Tokens provide secure authentication
Two-factor authentication significantly improves account security
GitHub provides web interface, desktop app, and CLI tools
The platform includes project management, CI/CD, and community features

Next Up: In the next lesson, we'll learn how to create and manage repositories on GitHub, including README files, licenses, and repository settings!