1. git?
   • git is a version control software
   • It keep track of code changes
   • It helps to collaborate in a project
   • It is installed and maintained locally
   • It provides Command Line Interface (CLI)
   • Released in April 7, 2005
   • Developed by Linus Torvalds & Junio C Hamano
2. github?
   • GitHub is a hosting service where we can keep our git repositiory/folders
   • It is maintained on cloud/web
   • It provides Graphical User Interface (GUI)
   • Founded in 2008

• Download and install git on your pc: https://git-scm.com/
• check git version: open terminal or cmd then use the command git --version to find out whether git is installed or not. if git is installed it will return a version number of git.

git configuration

1. check all configuartion options: git config
2. set global user name and user email for all repository/git folders (if you want to set different username and email for different git repository then remove --global)
   • set global user name: git config --global user.name "anisul-islam"
   • set global user email: git config --global user.email "[email protected]"
3. list all git configuration:
   • list all the configuration: git config --list
   • list user name: git config user.name
   • list user email: git config user.email
4. change global username & email
   • change global user name: git config --global user.name "PUT_NEW_USER_NAME_HERE"
   • change global user email: git config --global user.email "PUT_NEW_USER_EMAIL_HERE"

1. creating a git folder

• ls -a : list all files inside of a directory

  mkdir DIRECTORY_NAME_HERE
  cd DIRECTORY_NAME_HERE
  git init
  
  Example:
  mkdir notes
  cd notes
  git init
  ls -a
  

2. adding new files in git folder

• git status : displays the state of the working directory and staging area

  ls -a
  touch fileName.extension
  open fileName.extension
  git status
  
  Example:
  touch day1.txt
  open day1.txt
  write something inside the file
  

• Git is aware of the file but not added to our git repo

• Files in git repo can have 2 states – tracked (git knows and added to git repo), untracked (file in the working directory, but not added to the local repository)

• To make the file trackable stagging or adding is required

1. adding files to stagging area:

• git add fileName add a file in staging area / index
• git add . add all files of directory to stagging area not subdirectory
• git add -A add all files of directory and subdirectory to stagging area
• git rm --cached fileName unstage a file from staging area
• git diff - checking the differences of a staged file
• git restore fileName - restore the file

• git commit -m "message" move the file to local repository from stagging area
• git log check the commit history
• git reset --soft HEAD^ uncommit the commit in HEAD and move to staging area
• git reset HEAD^ uncommit the commit in HEAD and move to unstaging / working area
• git reset --hard HEAD^ uncommit the commit in HEAD and delete the commit completely with all the changes