What is the difference between the WHMCS module and WHMCS Users module?
OnApp WHMCS module (archived)
OnApp Users module
The WHMCS module allows you to create, build, reboot, shut down, start up, unlock, rebuild and delete virtual servers directly from WHMCS.
The WHMCS users module allows you to create, suspend and activate OnApp users through WHMCS, it can also handle invoicing and billing your clients.