What is the difference between AJAX and non-AJAX controller generation?

Non-AJAX controllers handle everything server-side with full page reloads. The list view loads all data at page load time (client-side DataTables), and form submissions do a standard POST with redirect. This mode is simpler, more debuggable, and more reliable across browsers. Use it as the default unless you have a specific reason not to. AJAX ResourceControllers use server-side DataTables pagination — the list lazy-loads data from a JSON endpoint, which scales better for large datasets. Forms in full-AJAX mode appear in Bootstrap modals and submit without page reloads. This mode is best for simple reference/lookup tables with few fields. It has known issues with Select2 in edit mode and does not support file uploads, so avoid it for complex entities.