# Notes on Git and GitHub

# What is Git?

Git is the most popular version-control system. There are other version-control systems such as Subversion.

## What is version-control system?

It saves -

* What changes was made to the source code?
    
* Who made the changes?
    
* When was the changes made?
    

## Why we use a version-control system?

* If an error was introduced to the source code, we can go to a previous version of code which did not have that error.
    
* If many people are working on the same source code, we can manage who makes what changes to the code.
    

### Download and Update Git

* Download: [Git - Downloads (](https://git-scm.com/downloads)[git-scm.com](http://git-scm.com)[)](https://git-scm.com/downloads)
    
* Update: `git clone https://github.com/git/git` *(Terminal Command)*
    

## Start Git

* Run `git init`
    
* This will create a folder: .git
    
* This is where history is saved.
    

# Git Commands

* `git status`: See what items are untracked/staged.
    
    * Untracked: Item is not on staging area.
        
        * Staging Area: Git can only process items on the staging area. Items must be put on the staging area before any work can be done.
            
    * Staged: Item is in staging area.
        
* `git add .` : Add items to the staging area
    
    * '.' means all items in the current directory.
        
    * Replace '.' with folder name to stage a particular item.
        
* `git commit -m "message"`: Store items in staging area to history.
    
* `git restore --staged .`: Remove item from staging area to untracked.
    
* `git log`: See history.
    
* `git reset fea46a6ef9c48a621b941cf04802930f8635e480`: Go back to a particular commit. All commits have a code associated with it which can be seen when `git log` is run.