This application is the file browser,code editor, and file versions self-contained in a single application.

The Text Editor is the file browser and the code editor self-contained in a single application.

File browser

Code editor

File versions

When you save a file after making a change, a new file version is created and stored locally. You can undo any change to a file by reverting to a previous version (this is different than git).

Read more here.