Git and GitHub Basics Explained for Complete Beginners

mkdir recipes && cd recipes
git init                          # start tracking this folder
echo "Masala chai: water, milk, tea, ginger" > chai.txt
git status                        # chai.txt is untracked
git add chai.txt                  # stage it
git commit -m "Add chai recipe"   # snapshot saved

echo "Add cardamom" >> chai.txt
git add chai.txt
git commit -m "Add cardamom to chai"
git log --oneline                 # list of snapshots
git show HEAD                     # what changed in the latest one
git diff HEAD~1 HEAD              # compare the last two snapshots

git switch -c spicy-version       # new branch
echo "Add black pepper" >> chai.txt
git commit -am "Try black pepper"
git switch main                   # back to the stable version
git merge spicy-version           # bring the change in
git branch -d spicy-version       # tidy up

# What a conflict looks like inside a file
<<<<<<< HEAD
Sugar: 1 spoon
=======
Sugar: 2 spoons
>>>>>>> sweeter-version
# Fix: keep the line you want, delete the markers, then
git add chai.txt
git commit -m "Resolve sugar conflict"

# After creating an empty repository on GitHub
git remote add origin git@github.com:yourname/recipes.git
git push -u origin main
git remote -v                     # shows where 'origin' points
git pull                          # later: get updates

git clone git@github.com:someone/project.git    # copy an existing repo
# Fork = your own copy of someone else's repo, made on GitHub.
# You push to your fork, then open a pull request to the original.
git remote add upstream git@github.com:someone/project.git
git fetch upstream                 # see their latest changes

Glossary
repository  folder tracked by Git, with full history
commit      saved snapshot with a message
HEAD        the commit you are currently on
branch      a movable pointer to a line of commits
merge       combine branches
remote      another copy of the repo (e.g. on GitHub)
origin      default name for your main remote
clone       copy a remote repo to your computer
fork        your own GitHub copy of someone else's repo
pull request a request to merge changes, with review

I want to...                     Command
start tracking a folder          git init
see what changed                 git status / git diff
save a snapshot                  git add . && git commit -m "msg"
see history                      git log --oneline
try something safely             git switch -c new-branch
combine work                     git merge branch-name
upload                           git push
download updates                 git pull

Everyday flow
1. git pull                 (start up to date)
2. git switch -c my-change  (work on a branch)
3. edit files
4. git add + git commit     (small, clear snapshots)
5. git push                 (share)
6. open a pull request on GitHub
7. merge after review, delete the branch