An Ultimate Guide to Git and Github

Last Updated : 19 Jul, 2025

In the world of software development, over 90% of developers use a version control system, with Git being the most popular choice. Git is a distributed version control system that allow developers to track changes in code, collaborate seamlessly, and manage projects efficiently. GitHub is built on top of Git, a cloud-based platform that provides a user-friendly interface for hosting, reviewing, and sharing code. Together, Git and GitHub have become essential for modern development, enabling open-source collaboration and enterprise-level project management.

In this article, we will cover everything you need to know about Git and GitHub. Whether you're new to version control or looking to brush up on your skills, this guide will serve as a one-stop solution for learning about Git. Let's get started!

Introduction to Git

A version Control system is a system that maintains different versions of your project when working in a team or as an individual. (System managing changes to files) As the project progresses, new features get added to it. So, a version control system maintains all the different versions of your project for you, and you can roll back to any version you want without causing any trouble to you for maintaining different versions by giving names to them, like MyProject, MyProjectWithFeature1, etc.

Distributed Version control system means every collaborator (any developer working on a team project)has a local repository of the project in his/her local machine unlike central where team members should have an internet connection to every time update their work to the main central repository.

So, by distributed we mean: the project is distributed. A repository is an area that keeps all your project files, images, etc. In terms of GitHub: different versions of projects correspond to commits.

For more details on the introduction to Github, you can refer: Introduction to Github

Key Git Concepts

Repository- A directory where git monitors your project files and records their revision history.
Clone- It created a local copy of a remote repository on your machine.
Stage - It Selects specific changes that you want Git to include in the next snapshot.
Commit- It records the staged changes as a permanent version in the project history.
Branch- Lets you develop new features or experiment without affecting the main project.
Merge- Integrates changes from one branch into another.
Pull- It fetches and applies updates from a remote repository to your local one.
Push- It Uploads your local commits to a remote repository

Git Repository Structure

It consists of 4 parts:

Working directory: This is your local directory where you make the project (write code) and make changes to it.
Staging Area (or index): this is an area where you first need to put your project before committing. This is used for code review by other team members.
Local Repository: this is your local repository where you commit changes to the project before pushing them to the central repository on Github. This is what is provided by the distributed version control system. This corresponds to the .git folder in our directory.
Central Repository: This is the main project on the central server, a copy of which is with every team member as a local repository.

All the repository structure is internal to Git and is transparent to the developer.

Some commands which relate to repository structure:

// transfers your project from working directory
// to staging area.
git add .

// transfers your project from staging area to 
// Local Repository.
git commit -m "your message here"

// transfers project from local to central repository.
// (requires internet)
git push

Note: For installation purposes on ubuntu, you can refer to this article: How to Install, Configure and Use GIT on Ubuntu?

Working with existing repos(git clone) and new repos(git init)

Git allows you to manage existing repository as well as new one.You can clone remote repository to work on a project that already exists, or initialize a new repository to begin tracking changes in a fresh project.

Working with existing repos (git clone)- When you are collaborating on a project that already exists on the remote platform like Github, you don't need to start from scratch . Instead you can clone the repository to your local machine using:

bash

git clone <repository-url>

This commands downloads the entire repository including its history, branches, and files.

bash

git clone https://github.com/username/project

Now you have a full copy of the project and can start contributed locally.

Started a new Repository (git init) - If you are beginning a brand new project you use:

bash

git init

This Command will create a new git repository in your current directory. It sets up a . git folder that will track all your changes made to files inside the project.

bash

mkdir my-project cd my-project git init

it will create a new folder , cd will redirect to current directory and git init will initializes a new empty repository.

How to Use `git merge` Effectively in Git

git merge is used to combine changes from one branch into another. It allows teams to work on different features or fixes in isolation and then bring work together . Merging Preserves the history of both branches and is a key part of collaborative workflows in git.

Switch the branch you want to merge into your changes

bash

git checkout main

Merge Changes from another branch into the current branch

bash

git merge feature-branch

If there are merge conflicts resolve them manually, then stage the changes

bash

git add .

Commit the merge if conflicts were resolved manually

bash

git commit

Creation of new Branch

Branches allows you to work on new features or fixes independently without affecting the main codebase. This isolates works and makes collaboration easier.

bash

git branch branch-name

Creating a new Branch without switching to it.

View All Branches

bash

git branch

Deletion of Branches

Once a branch has been emerged or no longer needed, you can delete it to keep your repo clean and organized.

Delete a local branch

bash

git branch -d branch-name

Deletes the branch if it has already been merged.

Force delete a local branch(unmerged changes)

bash

git branch -D branch-name

Delete the branch regardless of its mege status

Delete a remote branch

bash

git push origin --delete branch-name

Removes the branch from the remote repository (e.g., GitHub).

How to Use `git fetch` Effectively in Git

git fetch is used to download latest changes from a remote repository without automatically merging them into your current branch. It updates your local view of the remote branches, so you can review or merge changes .

Fetch all branch from the remote

bash

git fetch

Download update from the default remote (usually origin)

Fetch from a specific remote

bash

git fetch origin

Fetch from a specific branch

bash

git fetch origin feature-branch

Fetches only the feature-branch from the remote.

View changes after fetching

bash

git log HEAD..origin/main

It shows changes to your main branch that aren't not in your local branch.

How to Use `git stash` Effectively in Git

git stash is a handy git command that lets you temporarily save your uncommitted changes(both staged and unstaged) so you can switch branches or perform other tasks without losing your work. Once you're ready, you can reapply those changes exactly as you left them.

Stash your current changes

bash

git stash

Saves your changes and reverts your working directory to a clean state.

Stash with a custom message(recommended)

bash

git stash save "WIP: added login form"

Adds a label so you remember what was stashed.

View list all stashes

bash

git stash list

Displays stashes like stash@{0}, stash@{1}, etc.

Apply the most recent stash

XML

git stash apply

Restores the changes but keeps the stash in the list.

Apply a specific stash

bash

git stash apply stash@{1}

Apply and delete a stash in one step

XML

git stash pop

Clear all stash

XML

git stash clear

It removes all saved stashes.

Github

Github basically is a for-profit company owned by Microsoft, which hosts Git repositories online. It helps users share their git repository online, with other users, or access it remotely. You can also host a public repository for free on Github.

User share their repository online for various reasons including but not limited to project deployment, project sharing, open source contribution, helping out the community and many such.

Accessing Github central repository via HTTPS or SSH

Here, transfer project means transfer changes as git is very lightweight and works on changes in a project. It internally does the transfer by using Lossless Compression Techniques and transferring compressed files. Https is the default way to access Github central repository.

By git remote add origin http_url: remote means the remote central repository. Origin corresponds to your central repository which you need to define (hereby giving HTTPS URL) in order to push changes to Github.
Via SSH: connect to Linux or other servers remotely.

If you access Github by ssh you don't need to type your username and password every time you push changes to GitHub.

Terminal commands:

ssh-keygen -t rsa -b 4096 -C "[email protected]"
This does the ssh key generation using RSA cryptographic algorithm.

eval "$(ssh-agent -s)" -> enable information about local login session.

ssh-add ~/.ssh/id_rsa -> add to ssh key.
cat ~/.ssh/id_rsa (use .pub file if not able to connect)
add this ssh key to github.

Now, go to github settings -> new ssh key -> create key

ssh -T [email protected] -> activate ssh key (test connection)

Refresh your github Page.

Working with git - Important Git commands

Git user configuration (First Step)

git --version (to check git version)
git config --global user.name "your name here"
git config --global user.email "your email here"

These are the information attached to commits.

Initialize directory

git init

initializes your directory to work with git and makes a local repository. .git folder is made (OR)

git clone http_url

This is done if we have an existing git repository and we want to copy its content to a new place.

Connecting to the remoterepository

git remote add origin http_url/ssh_url

connect to the central repo to push/pull. pull means adopting the changes on the remote repository to your local repository. push merges the changes from your local repository to the remote repository.

git pull origin master

One should always first pull contents from the central repo before pushing so that you are updated with other team members' work. It helps prevent merge conflicts. Here, master means the master branch (in Git).

Stash Area in git

git stash

Whichever files are present in the staging area, it will move that files to stash before committing it.

git stash pop

Whenever we want files for commit from stash we should use this command.

git stash clear

By doing this, all files from stash area is been deleted.

Steps to add a file to a remote Repository:

First, your file is in your working directory, Move it to the staging area by typing:

git add -A (for all files and folders)
#To add all files only in the current directory
git add .

git status: here, untracked files mean files that you haven't added to the staging area. Changes are not staged for commit means you have staged the file earlier than you have made changes in that files in your working directory and the changes need to be staged once more. Changes ready to be committed: these are files that have been committed and are ready to be pushed to the central repository.

git status

git commit -a -m "message for commit"
-a: commit all files and for files that have been 
     staged earlier need not to be git add once more
-a option does that automatically.

git push origin master -> pushes your files to 
                         github master branch
git push origin anyOtherBranch -> pushes any 
                      other branch to github.
git log ; to see all your commits

git checkout commitObject(first 8 bits) file.txt-> 
revert back to this previous commit for file file.txt

Previous commits might be seen through the git log command.

HEAD -> pointer to our latest commit.

Ignoring files while committing

In many cases, the project creates a lot of logs and other irrelevant files which are to be ignored. So to ignore those files, we have to put their names in".gitignore" file.

touch .gitignore
echo "filename.ext" >>.gitignore
#to ignore all files with .log extension
echo "*.log" > .gitignore

Now the filenames written in the .gitignore file would be ignored while pushing a new commit. To get the changes between commits, commit, and working tree.

git diff

The 'git diff' command compares the staging area with the working directory and tells us the changes made. It compares the earlier information as well as the current modified information.

Branching in Git

create branch ->
git branch myBranch
or
git checkout -b myBranch -> make and switch to the 
                                  branch myBranch

Do the work in your branch. Then,

git checkout master ; to switch back to master branch

Now, merge contents with your myBranch By:

git merge myBranch (writing in master branch)

This merger makes a new commit.

Another way

git rebase myBranch

This merges the branch with the master in a serial fashion. Now,

git push origin master

To remove or delete a file

To remove. a file from the Git repository we use

git rm “file name”

To remove only from the staging area

git rm –cached “ file name”

Undoing change

To change all the files to as same as the previous commit then use

git checkout -f

Git vs Github

Git and GitHub are often mentioned together, but they serve different purposes. Git is a local tool used for tracking changes in your code, while GitHub is an online platform for hosting and sharing Git repositories. Together, they enable powerful version control and team collaboration in software development.

Feature	Git	Github
Type	Version control system (VCS)	Web based Hosting Service
Function	Tracks and manages code changes locally	Stores Git repositories in the cloud and enables collaboration
Installation	Must be installed on your system	Accessible through a web browser (no installation needed)
Usage	Used for local version control and branching	Used for sharing, reviewing, and managing Git projects online
Collaboration	Limited to local or manual sharing	Real-time collaboration with teams and contributors
Interface	Command-line tool (CLI)	Web-based UI and also supports Git CLI
Main Purpose	Track code history and manage changes locally	Centralized hub to host, view, and contribute to Git projects
Offline Support	Fully functional offline	Requires internet to access remote features

Contributing to Open Source

Open Source might be considered as a way where user across the globe may share their opinions, customizations or work together to solve an issue or to complete the desired project together. Many companies host there repositories online on Github to allow access to developers to make changes to their product. Some companies (not necessarily all) rewards their contributors in different ways.

You can contribute to any open source project on Github by forking it, making desired changes to the forked repository, and then opening a pull request. The project owner will review your project and will ask to improve it or will merge it.

Conclusion

In simple terms, Git is a powerful tool for managing your projects and code changes. It helps you keep your work organized, collaborate with others, and easily track your progress. Whether you're working alone or in a team, Git and GitHub make sure that you can manage your code, avoid errors, and never lose your work. It’s a must-learn for anyone who codes!

Sushant Oberoi

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Article Tags :

Practice Tags :

Misc

An Ultimate Guide to Git and Github

Introduction to Git

Key Git Concepts

Git Repository Structure

Working with existing repos(git clone) and new repos(git init)

How to Use git merge Effectively in Git

Creation of new Branch

Deletion of Branches

How to Use git fetch Effectively in Git

How to Use git stash Effectively in Git

Github

Accessing Github central repository via HTTPS or SSH

Working with git - Important Git commands

Git vs Github

Contributing to Open Source

Conclusion

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