The Project Explorer is the main pane on the left of the Help+Manual window. It provides direct access to all the components of your projects, including both topics and settings. This is where you select topics for editing, create new topics, change the structure of your project and configure all your project's settings.

Help+Manual Project Explorer

Help+Manual Project Explorer

Editing: Just select an item in the Project Explorer to view it for editing in the Editor.

Multiple projects: You can load multiple projects into the Explorer and work on them all at the same time, for example to copy and paste between projects and to work on the components of modular help systems.