Project Workspace
This article concerns the
macOS
app.
See other variants:
iOS
Windows

When a file is opened with Texifier, a workspace is created for it.

A root file is a file that contains a block of LaTeX (or plain TeX) source code that is a valid candidate for typesetting into an output PDF.

docs/apps/workspace/overview.svg

This is a window persistent state of the entire project for that file, including the typeset configuration, the states editor tabs are in as well as various other pieces of information that help Texifier to restore the project to its current state when you close it and reopen it.