Themes control presentation
Themes mainly define layout, typography, templates, and visual styles.
Plugins add functionality
Forms, integrations, custom post types, and business logic should generally remain active when the theme changes.
Avoid lock-in
Document essential features and ensure you can export or migrate their data.
Test the switch
Before choosing a theme, check that important content remains accessible after switching.
Further reading
This guide is educational. Check current documentation before making technical or purchasing decisions.