World 1: Save Points

Your first save point

You will learn: how to make a commit, and what is inside one.

The problem

Tonight your home page works. Tomorrow you might break it. Can you get tonight’s version back? Only with a save point.

Watch

git commit takes a snapshot: a full photo of the box, right now. The words after -m are a short note about it.

Try it

Save index.html as a new commit.

Working folder

Staging area

Empty

Repository

1 save point
Add README

Hint

Two steps: git add index.html, then git commit -m "Add home page".

Watch

~/diary $ git logcommit e9e6425fe682d4e9e3c76b84e4da6a3be9cb459f (HEAD -> main)Author: You <you@example.com>Date:   Fri Oct 30 09:02:00 2026 +0800    Add home pagecommit 6d3a9b115cdb7b7a74eab7cb29b0a98526fb9777Author: You <you@example.com>Date:   Fri Oct 30 09:01:00 2026 +0800    Add README

git log lists your commits, newest first. The long code after “commit” is the hash. It is that commit’s unique name.

Watch

Each new commit points back to the one before it. That older commit is its parent. Together they make your timeline.

Check

Which one is NOT saved inside a commit?

Try it

Now do it for real, on your own computer. Type each command yourself. Copy only if you get stuck.

Real mission

Open your terminal. On Windows, use Git Bash.
Make a new folder.
mkdir real-diary
Go inside it.
cd real-diary
Make it a repo.
git init
Make a home page file.
echo "<h1>My Diary</h1>" > index.html
Put it in the box.
git add index.html
Save it with a message.
git commit -m "Add home page"
Read it. Find your name, the date and the hash.
git log

0 of 8 steps done · Your ticks are saved.

Hint

Stuck inside git log? Press q to get out.

You did it!

You can now make a commit and read it in git log.

Go deeper (optional)

git show prints the newest commit and exactly what changed in it. Want a longer note? Add a second -m. The first one becomes the title, the second the body.

~/diary $ git showcommit e9e6425fe682d4e9e3c76b84e4da6a3be9cb459f (HEAD -> main)Author: You <you@example.com>Date:   Fri Oct 30 09:02:00 2026 +0800    Add home pagediff --git a/index.html b/index.htmlnew file mode 100644index 0000000..a8ad0de--- /dev/null+++ b/index.html@@ -0,0 +1,2 @@+<h1>My Diary</h1>+<p>Day 1: I learned Git.</p>