Simple definition
The WordPress Site Editor lets users customize block-theme templates, navigation, and global styles.
Purpose and use
The Site Editor customizes templates, styles and shared components of a compatible theme.
How does it work?
It distinguishes structural objects from individual publication content, even when both appear in one visual editing interface.
Example and verification
After changing a header or template, check relevant page types and mobile and desktop displays.
Points to watch
One page preview does not cover every use of a component. User permissions and theme capabilities also determine available options.
In short
Using the editor requires understanding which object is saved and the scope of publishing it.