Local Version Control
Repositories and commits
Understand Git's snapshot model.
8 minutes - Absolute beginner
What this means
A repository stores project history. A commit is a named snapshot with an author, time, message, and parent relationship.
In beginner terms, this topic answers one practical question: "What should I write, and why does React care about it?" Do not try to memorize the syntax first. First understand the idea, then connect the syntax to that idea.
Why it matters
Small meaningful commits make changes reviewable and reversible.
When you build real React screens, this idea helps you decide where data should live, what the user should see, and what should happen after an interaction. That is why this lesson is part of the main path instead of being an optional detail.
Step by step
1. Notice the UI problem this topic solves. 2. Look at the smallest possible example. 3. Change one value and predict what should appear. 4. Run the example and compare the result with your prediction. 5. Use the practice task before moving on.
Small example
git init
git add app.ts
git commit -m "Add lesson page"Common mistake
Do not copy repositories and commits syntax without explaining what problem it solves and checking the result.
Practice task
Change one part of the example, predict the result, run it, and explain the result in your own words.
Remember this
A commit should represent one coherent change.
try.it
Examples
Try it: Repositories and commits
Edit this focused Git example and run it in the browser preview.
Preview runs browser-safe JavaScript in a sandboxed frame, never on the server.
editor
preview
Login to save progress
You can read lessons without an account, but progress requires login.