Final answer:
A CD-ROM can store about 700MB, enough for an encyclopedia or 80 minutes of audio. A DVD-ROM has a larger capacity, with single-layer DVDs holding about 4.7GB and dual-layer up to 8.5GB, thanks to shorter-wavelength laser technology.
Step-by-step explanation:
The storage capacity of a CD-ROM disk typically holds about 700 megabytes of data, which is enough to store an entire encyclopedia or approximately 80 minutes of audio. DVDs on the other hand, have a much larger capacity due to their ability to store information on multiple layers and more densely thanks to the use of a shorter-wavelength laser. A single-layer DVD-ROM disk can store about 4.7 gigabytes, and a dual-layer DVD can hold up to 8.5 gigabytes of data.