an Entity references as follows:
A combo drive is a type of optical drive that combines CD-R/CD-RW recording capability with an ability to read (but not write) DVD media; some manufacturers refer this as CD-RW/DVD-ROM drive. The term is used almost exclusively by Apple Inc. as a name for the low-end substitute for their high-end SuperDrive, as the latter was designed to both read and write CD and DVD recordable media. The device was created as a mid-range option between a CD burner and a DVD burner, which at the time the combo drive was introduced was generally an expensive option costing in excess of US$300 a unit.