What is a HEAD

Pointer that points to the commit from which the working tree's current state was initialized.

• Could be wherever you are in the commit history.

What is a Working Tree

Working tree are the files that you are currently working on

What is an Index

index is a place where you prepare your changes before committing them (before commit, you add the files to the index)

• index is also known as cache, directory cache, current directory cache, staging area, staged files