The account details are used to login to the software which is verified over a secure connection to Volvo's server. To access the system, a subscription is required that gives you an user account.
The VIDA software on the PC was built on a MS Access database that held all the diagnostic routines, parts lists and repair information on a per-model and model year basis (which it works out by decoding the VIN). Genuine DICE units are available to VIDA subscribers from Volvo's diagnostics system supplier (Bosch) for about £500-£600. It consists of 2 parts - a suite of software applications that run on a host PC (and connect to Volvo's manufacturing database servers to read and update information about the vehicle) and a hardware interface (called DICE) that plugs into the vehicle's OBDII diagnostic port and connects to the host PC over USB or Bluetooth (or latterly WiFi). VIDA (Vehicle Information and Diagnostic tool for Aftermarket) is the terminal used by Volvo dealers (and third-party subscribers) for performing diagnostics, ordering parts, viewing repair instructions, wiring diagrams and downloading software updates to vehicles.