A place to hide modifications while you work on something else.
Workspace
Also called ‘working copy’, ‘working tree’ or just ‘checkout’
Local checkout of your code.
It’s any directory on your filesystem that has a repository associated with it (typically indicated by the presence of a sub-directory within it named .git).
It includes all the files and sub-directories in that directory
Index
A staging area for file changes to commit.
Before you “commit” (or checkin) files, you need to first add them to the index.
This is also called “current directory cache”, “staging area”, “cache” or “staged files
Local repository
A directory named .git that contains all of your necessary repository files — a Git repository skeleton.