Local Repository

In the working Directory:

   git init                        //to initialise the git 

   git status                      // to get status of the staging area and commits
   
   git add .                       // add all the files of working directory to staging area
   
   git add [filename]              //add that file to the staging area
   
   git commit -m "commit_msg"      //to commit all files from staging area to local repository
   
   git log                         // to get log of previous commits
   
   git checkout [filename]         // to revert back the changes to previous version of that particular file
   
   git diff [filename]             // give difference between cureent and previous version of that file

Remote Repository

Pushing files to existing repo

In the working Directoy

   git remote add origin [url of the repository]

   git push -u origin master // pushes all files to the master branch of remote repository

Cloning a Repository

In the directory where you want to clone the repo

git clone [url of repository]

Branching and Merging

   git checkout [branch_name]    //switch to that branch
   git branch                    // shows the current working branch
   
   // To merge a branch to master branch, in master branch type:
   
   git merge [branch_name]

.gitignore

  // To ignore some files (may be secrets which committing in public repo may be risky):
  // In the working Directory
  
  touch .gitignore
  
  // In the .gitignore file name the files which you want to ignore like this:

   file1.txt
   file2
   and so on..
   
   # To add comment in .gitignore file
   
   # use *.txt to ignore all txt files