The Playground
A local repository that exists to be experimented on.
The Playground is a repository Innesta creates for you, locally, with the express purpose of being a place to try things.
It matters because most of what is worth learning about Git is worth learning somewhere it cannot cost anything. Rebasing, resolving a conflict, resetting hard, deleting a branch and getting it back — all of those are much easier to understand once you have done them, and much harder to try for the first time on work you care about.
What is in it
A local repository with a small amount of history, on your disk like any other. It is not connected to a server and it is not connected to any of your other repositories.
It can optionally be set up with GitFlow branches, which is a good way to see what that workflow actually does to a repository before turning it on somewhere real.
Creating one
Onboarding offers it as one of the ways to get started: it asks where to put the folder and creates it there. That is where it is offered — the welcome screen’s own buttons are Open Repository…, Clone… and New….
Getting rid of it
It is a folder. Delete it in Finder, and remove the entry from the Projects list.