Dynaload was released with PC-DOS 7.0 by IBM. It can load device drivers (sys-files like your cd-rom driver) into memory from the command prompt, without requiring a reboot.
This utility can be used to make a batch file which loads the CD-ROM drivers, so if they haven't been loaded then you can load them on demand using the batch without needing to reboot.
It can also be used in the DOSSTART.BAT which is executed by Win9x when doing "Exit To DOS", so one don't need to have the DOS CD-ROM drivers loaded in the CONFIG.SYS anymore.
Note Creative have created a similar tool called Ctload.