Git and GitHub

Git and GitHub are essential tools in modern software development, enabling version control and collaboration among developers.

Git

Version Control System:

Git is a distributed version control system (DVCS) that helps track changes in source code during software development.

Concepts of Git:

Repository (Repo): A storage location for a project's files and revision history.

Clone: Copying a repository to create a local copy on your machine.

Commit: A snapshot of changes made to the code.

Branch: A separate line of development that allows changes to be made without affecting the main codebase.

Merge: Combining changes from one branch into another.

Pull: Fetching changes from a remote repository to update the local copy.

Push: Uploading local changes to a remote repository.

Git Commands:

SETUP

Configuring user information used across all local repositories

Define the author name to be used for all commits by the current user.
```
git config --global user.name <Username>
```

Define the author email to be used for all commits by the current user.
```
git config --global user.email <User_email>
```

SETUP & INIT

Configuring user information, initializing and cloning repositories

initialize an existing directory as a Git repository
```
git init
```

retrieve an entire repository from a hosted location via URL
```
git clone <Url>
```

STAGE & SNAPSHOT

Working with snapshots and the Git staging area

List which files are staged, un staged, and untracked.
```
git status
```

Add a file as it looks now to your next commit (stage)
```
git add <file>
```

Remove <file> from the staging area, but leave the working directory unchanged. This unstages a file without overwriting any changes
```
git reset <file>
```

Show un staged changes between your index and working directory.
```
git diff
```

diff of what is staged but not yet committed
```
git diff --staged
```

Commit the staged snapshot, but instead of launching a text editor, use <descriptive_message> as the commit message
```
git commit -m <descriptive_message>
```

BRANCH & MERGE

Isolating work in branches, changing context, and integrating changes

list your branches. a * will appear next to the currently active branch
```
git branch
```

create a new branch at the current commit
```
git branch <branch_name>
```

switch to another branch and check it out into your working directory
```
git checkout
```

merge the specified branch’s history into the current one
```
git merge <branch>
```

Display the entire commit history using the default format. For customization see additional options.
```
git log
```

REMOTE REPOSITORIES

Retrieving updates from another repository and updating local repos

Create a new connection to a remote repo. After adding a remote, you can use <name> as a shortcut for <url> in other commands.
```
git remote add <name> <url>
```

fetch down all the branches from that Git remote
```
git fetch <name>
```

merge a remote branch into your current branch to bring it up to date
```
git merge <name>/<branch>
```

Transmit local branch commits to the remote repository branch
```
git push <name> <branch>
```

fetch and merge any commits from the tracking remote branch
```
git pull
```

GitHub

GitHub is a web-based platform that provides hosting for Git repositories and additional Collaboration features.

Collaboration in GitHub:

Pull Requests (PRs):
- Proposed changes to a repository submitted by a developer for review before being merged.

Issues:
- Track tasks, enhancements, bugs, and other kinds of questions.

Forks:
- Personal copies of another user's repository for making changes without affecting the original project.

Workflow:

Forking a Repository:
- Create a personal copy of someone else's project.

Cloning:
```
git clone <repository_url>
```

Branching, Committing, and Pushing:
- Similar to the Git workflow on your local machine.

Pull Request:
- Submit changes for review and merge.

Merging Pull Request:
- Once changes are approved, they can be merged into the main repository.

GitHub provides a user-friendly interface for Git operations and enhances collaboration in a team setting. Many open-source projects and organizations use GitHub as a platform for hosting and managing their repositories.

Differences between Git and GitHub

Feature	Git	GitHub
Definition	Distributed Version Control System (DVCS)	Web-based platform for hosting Git repositories
Type	Software installed locally	Web-based service
Functionality	Manages version control locally	Adds collaboration features, remote hosting
Repository Hosting	Local machine	GitHub servers
Collaboration	Limited (local team)	Extensive (global collaboration)
Remote Repositories	Can be hosted on any server	Hosted on GitHub servers
Graphical Interface	Command-line	Web-based with a graphical interface
Pull Requests	Not applicable	Facilitates code review and collaboration
Issues and Tracking	Not applicable	Integrated issue tracking system
Forking	Not applicable	Allows users to create personal copies (forks)
User Management	Not applicable	User permissions, teams, and organization
Visibility	Limited to local machine	Public and private repositories
Use Cases	Local version control and development	Collaborative software development, open source