Unit 10: Git & GitHub

Git is not a cloud backup button. It is a system for recording and comparing project states.

GitHub can host and share Git repositories, but the local repository still has its own working tree, staging area, commits, branches, and history.

Learn the states before the commands

You will use commands such as git status, git diff, git add, git commit, and git log, but the important question is what state each command reveals or changes.

working files
   -> inspected change
   -> selected/staged change
   -> commit
   -> repository history
   -> optional remote publication

A commit is useful when it records a coherent, understood checkpoint. A giant “stuff” commit after three hours of unrelated edits is technically history but weak engineering evidence.

This Unit also treats secret handling as part of repository design. A token committed and later deleted may still exist in history. “I removed the line” is not the same thing as “the secret was never exposed.”

Repository evidence

Build a small history you can explain. Keep at least three meaningful commits, inspect the diff before one of them, introduce and repair one bug, and use git log or commit inspection to reconstruct what changed.

The final skill is not pushing to GitHub. It is being able to answer: what state is my project in, what changed, and how do I know?