Repository
Also called Repo
One project under version control: your files, plus a hidden folder called .git that holds the entire history. Run git init in a folder and it becomes a repository. Delete .git and the history is gone.
The whole history sits on your machine, in a folder an agent can reach. Reading it is how an agent catches up at the start of a session, and damaging it is one of the few ways it can really hurt you, which is why agent tools treat that folder as special.
Say it to your agent
“Run git init, add a .gitignore covering node_modules and .env, and make a first commit called "chore: initial commit" before you write any code, so every change after this can be seen and undone.”