§ how it works · git
Each card below is an SVG visualization of one Git concept: how a file on disk becomes a commit, what "branches diverged" means, and where exactly --force-with-lease can betray you. A map where every ref has its place, rather than a list of commands.
These are drawn diagrams, not a sandbox. To get hands-on, go to the lessons with automatic checks.
objects · 5 steps
Inside, Git is four object types and one big hash table. Let's see how a file on disk turns into a commit with a SHA, and why the whole history is cryptographically linked.
history · 5 steps
You "merged the branch" but how? Without a merge commit or with one? What does "branches diverged" mean, and why does --no-ff exist? The commit graph shows it all in a second.
collaboration · 5 steps
Why --force-with-lease exists, exactly how it protects you from overwriting someone else's commits, and why a background fetch can fool it. Three zones, five scenarios.