The system theme controls the appearance of the Client Area and your online store.
You can easily change the logo in emails, on generated invoices, and in the Client Area.
You can enable search-engine-friendly URLs for some public-facing pages.
In some circumstances, you must force WHMCS to perform a license update.
When you move your WHMCS installation, you may need to perform additional steps like updating your license.
You can take steps to optimize performance on larger installations.
You can use cPanel's MultiPHP Manager and MultiPHP INI Editor features to upgrade PHP.