Drivers are files which contain configuration information on modems and other hardware.
They are platform-specific, and used when installing new hardware into a system. These files are usually provided on a diskette or CD-ROM with the modem, but occasionally an updated driver will be made available to fix a bug or provide improved performance. This is memory that maintains its contents during normal operation, but can be over-written by special commands. This way, if a bug in the code is discovered or new features become available, all you need to do to replace your modem's firmware is to run a special program that replaces the contents of the Flash RAM with the corrected or improved code. Then type ATI3 and the firmware revision will be displayed.