Disk Writing Software are designed to seek this information about all relevant parameters like Type of Disk, Complete/Incomplete, Free Space if any, Bootable etc and most have a menu option to just seek the Disk Info. This will anyways reveal the type of Media be it CD/DVD, -R, +R, ROM etc.
See sample screenshot below from BurnAware Free Application. I inserted DVD-R, DVD-ROM, CD-R & CD-ROM media in the drive and each time it correctly displayed the type. Hope this helps.