Introduction to GitHub

GitHub is the world's largest platform for hosting and collaborating on Git repositories. It adds powerful features on top of Git that make collaboration easier.

What is GitHub?

GitHub is a web-based platform that provides:

• Repository hosting: Store your Git repos in the cloud
• Collaboration tools: Work with teams on code
• Social features: Follow developers, star projects
• Project management: Issues, projects, milestones
• Automation: GitHub Actions for CI/CD
• Documentation: Wikis, README rendering

Git vs GitHub

Git	GitHub
Version control software	Cloud hosting platform
Runs on your computer	Runs in the cloud
Command-line tool	Web interface + API
Free, open source	Free tier + paid plans
Works offline	Requires internet

You can use Git without GitHub (using GitLab, Bitbucket, or self-hosted), but most developers use GitHub.

Key GitHub Concepts

Repository

A repository on GitHub contains:

• Your project's files
• Complete Git history
• Issues and discussions
• Pull requests
• Project settings

Owner Types

Type	Description
User	Personal account (github.com/username)
Organization	Team/company account (github.com/org)

Visibility

Visibility	Who can see
Public	Anyone on the internet
Private	Only you and collaborators
Internal	Organization members (Enterprise)

The GitHub Interface

Repository Page

┌─────────────────────────────────────────────────────────┐
│  owner/repository                          Star  Fork   │
├─────────────────────────────────────────────────────────┤
│  Code  Issues  Pull requests  Actions  Projects  Wiki   │
├─────────────────────────────────────────────────────────┤
│  main ▼  |  branches  |  tags  |  Go to file  |  Code ▼ │
├─────────────────────────────────────────────────────────┤
│                                                         │
│  📁 src/                                               │
│  📁 tests/                                             │
│  📄 README.md                                          │
│  📄 package.json                                       │
│                                                         │
├─────────────────────────────────────────────────────────┤
│  README.md                                              │
│  ─────────────────────────                              │
│  # Project Name                                         │
│  Description of the project...                          │
└─────────────────────────────────────────────────────────┘

Main Tabs

Tab	Purpose
Code	Browse files, view README
Issues	Bug reports, feature requests
Pull requests	Proposed code changes
Actions	CI/CD workflows
Projects	Kanban boards, planning
Wiki	Documentation
Security	Vulnerability alerts
Insights	Analytics, graphs
Settings	Repository configuration

GitHub Features

Stars

"Starring" a repository is like bookmarking it:

• Shows appreciation
• Saves to your starred list
• Helps repositories gain visibility

Forks

A fork is your personal copy of someone else's repository:

• Full copy under your account
• Can make changes freely
• Used for contributing to projects

Watch

Get notifications about repository activity:

• Participating: Issues/PRs you're involved in
• All Activity: Every issue, PR, commit
• Ignore: No notifications
• Custom: Choose what to watch

Free vs Paid Plans

Free Tier Includes

• Unlimited public/private repos
• Unlimited collaborators
• 2,000 Actions minutes/month
• 500MB Packages storage
• Community support

Paid Plans Add

• More Actions minutes
• Required reviewers
• SAML/SSO
• Advanced audit log
• Enterprise features

Getting Started

Sign Up

1. Go to github.com
2. Click "Sign up"
3. Choose username (choose carefully - it's your identity)
4. Verify email
5. Complete setup

First Steps

1. Set up your profile: Add photo, bio
2. Configure SSH: For passwordless authentication
3. Explore: Browse popular repositories
4. Star: Save interesting projects
5. Follow: Follow developers you admire

The GitHub CLI

GitHub provides a CLI tool called gh:

# Install (macOS)
brew install gh

# Authenticate
gh auth login

# Create repo
gh repo create my-project --public

# Clone repo
gh repo clone owner/repo

# Create issue
gh issue create --title "Bug" --body "Description"

# Create PR
gh pr create --title "Feature" --body "Description"

Markdown on GitHub

GitHub renders Markdown beautifully:

# Heading

**Bold** and *italic* text.

- Bullet
- Points

1. Numbered
2. List

`inline code`

```python
def hello():
    print("Hello, World!")

Link

### Special Markdown Features

- Task lists: `- [ ] Todo` / `- [x] Done`
- Mentions: `@username`
- Issue references: `#123`
- Emoji: `:rocket:` → 🚀
- Tables, footnotes, alerts

## Summary

- GitHub is the leading platform for Git repository hosting
- Key features: repos, issues, PRs, Actions
- Free tier is generous for most users
- Stars, forks, and watching help you engage with projects
- GitHub CLI (`gh`) provides command-line access
- Markdown is rendered throughout the platform

In the next lesson, we'll learn how to create repositories on GitHub.