Which of the following are optical storage devices? (select three)

Optical storage devices are media that use lasers to read and write data. This type of storage relies on light to access the information encoded on the surface of the media. The correct selections in this context would include Blu-ray Disks, HD DVDs, and CDs, as they all utilize optical technology.

Blu-ray Disks specifically have a high storage capacity compared to traditional CDs and DVDs due to their use of shorter wavelength blue lasers, which allow for more data to be packed into the same physical space. They are commonly used for high-definition video and data storage.

CDs (Compact Discs) represent an earlier generation of optical storage, primarily used for music and smaller data files. They operate using lasers to read the bumps on the disc's surface, which represent the stored information.

HD DVDs serve as a transitional technology that competes with Blu-ray, allowing for high-definition video storage as well. Although they have largely been replaced by Blu-ray in practical use, they still illustrate the principles of optical storage by utilizing similar laser technology.

In contrast, a USB flash drive is a form of solid-state storage that uses flash memory, which is fundamentally different from optical storage as it does not rely on lasers for data retrieval.