A Digital Versatile Disk (DVD) is an example of a computer storage device. It is a type of optical disc that can store large amounts of data, including movies, music, and software. DVDs use laser technology to read and write data, and can hold up to 4.7 gigabytes of information on a single-sided, single-layer disc. They are commonly used for entertainment purposes, such as watching movies or listening to music, as well as for storing backups of important files and documents.