Github Full Basics & Practical Guide

This guide covers GitHub only (remote repositories, collaboration, organizations, PRs, permissions, .gitignore, README best practices). It assumes you already know Git basics (init, add, commit, branches, merge, rebase).

Why Github?

GitHub is a cloud platform for hosting Git repositories and enabling collaboration.

Use cases:

• Personal storage: Keep your projects backed up online and accessible from anywhere.

• Multi-developer collaboration: Multiple developers can work on the same codebase.

• Contributions & open-source: Contribute to public projects, submit fixes and features.

• Code review: Pull Requests enable discussion and review before merging.

• Issues & project management: Track bugs, features, and tasks.

• CI/CD integrations: Automate testing and deployments.

Github Repositories (remote)

Create a New Repo Locally and Connect to Github

echo "# git_playground" >> README.md
git init
git add README.md
git commit -m "first commit"
git branch -M main
git remote add origin https://github.com/USERNAME/git_playground.git
git push -u origin main

Connect an Existing Local Repo to Github

git remote add origin https://github.com/USERNAME/git_playground.git
git branch -M main
git push -u origin main

Explanation

git branch -M main

• -M forcefully renames the current branch to main (instead of master or any other name).

git remote add origin https://github.com/USERNAME/repo.git

• remote: connect your local repo to a remote repo on GitHub.

• origin: a shortcut name for the remote URL (you can name it anything, but origin is the convention).

git push -u origin main

• push: upload your commits to GitHub.

• origin: remote name (URL shortcut).

• main: target branch on GitHub.

• -u (upstream): sets the default remote/branch so next time you can use git push only.

Authentication & Common Error (403)

You might see:

remote: Permission to USER/repo.git denied.
fatal: unable to access 'https://github.com/USER/repo.git/': 403

Why this happens:

• You’re not authenticated.

• You don’t have permission on that repo.

• You’re using HTTPS without a Personal Access Token (PAT).

Fix (Recommended):

• Use GitHub Personal Access Token (PAT) instead of password.

• Or use SSH keys and push via SSH URL:

git remote set-url origin git@github.com:USERNAME/repo.git

Remote Branches & Tracking

List all branches (local + remote-tracking):

git branch -a

List remote-tracking branches only:

git branch -r

Fetch vs Pull

git fetch origin

• Updates remote-tracking branches only.

• Does not change your local working branch.

git pull origin main

• pull = fetch + merge

• Updates your local branch with remote changes.

Deleting Remote Branches

Delete locally:

git branch -D branchname

Delete on GitHub (remote):

git push origin --delete branchname

Note: --delete removes the branch from the remote repository.

Cloning a Repository

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

This downloads the repo and automatically sets:

• origin remote

• default upstream branch

Fork & Pull Request (pr)

Fork

• A fork is your personal copy of someone else’s repository on your GitHub account.

• Used when you don’t have write access to the original repo.

Typical Fork Workflow

1. Fork the repo on GitHub.

2. Clone your fork:

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

1. Add upstream (original repo):

git remote add upstream https://github.com/ORIGINAL_OWNER/repo.git

1. Create a feature branch:

git switch -c feature-x

1. Push changes to your fork:

git push origin feature-x

1. Open a Pull Request from your fork → original repo.

Pull Request (pr)

• A PR is a request to merge your changes into another branch/repo.

• Enables:

  • Code review

  • Discussion

  • CI checks before merge

Github Organizations

Organizations are used to manage teams, permissions, and repositories for companies, teams, or communities.

Benefits

• Centralized repo ownership

• Role-based access control

• Teams for managing permissions

• Better security & auditing

• Scales well for large teams

Roles & Permissions

Members

• Part of the organization.

• Can be assigned to teams.

• Permissions depend on team/repo access.

Outside Collaborators

• Not organization members.

• Granted access to specific repositories only.

• Useful for contractors or external contributors.

Teams

• Group members into teams (e.g., Backend, Frontend, DevOps).

• Assign permissions to teams instead of individuals:

  • Read: view code

  • Triage: manage issues/PRs

  • Write: push to repo

  • Maintain: manage repo settings (limited)

  • Admin: full control

Permissions Scope

Permissions can be applied at:

• Organization level

• Team level

• Repository level

This gives fine-grained control over:

• Who can push

• Who can review

• Who can manage settings

.gitignore (secrets & Private Files)

Use .gitignore to prevent sensitive or unnecessary files from being pushed:

Examples:

• API keys

• Secret tokens

• Environment files

• Build artifacts

• IDE configs

Example .gitignore:

.env
*.key
*.pem
node_modules/
build/
dist/

⚠ Never push secrets to GitHub. If you did, rotate the key immediately.

Readme Files on Github

Repository Readme

• Explains:

  • What the project does

  • How to install

  • How to run

  • How to contribute

  • License

Github Profile Readme

Create a repo named exactly like your username:

USERNAME/USERNAME

Your README.md will appear on your GitHub profile.

You can use profile README generators to quickly scaffold sections like bio, skills, stats, badges, and featured projects.

Best Practices

• Use SSH or PAT for authentication

• Protect main branch (require PRs)

• Use meaningful PR titles & descriptions

• Review code before merging

• Keep secrets out of repos

• Use Issues for tracking work

Summary

• GitHub is for hosting, collaboration, and code review.

• Use push/pull/fetch to sync with remote.

• Use fork + PR when you don’t have write access.

• Use organizations & teams for scalable permission management.

• Protect secrets with .gitignore.

• Write a clear README for every repo.

End of GitHub Guide 🚀