A DVD writer is a device that allows users to record data onto DVDs, which are optical discs used for storing video, audio, and other digital information. It functions by using a laser to etch data onto the disc's surface, enabling the creation of movies, music compilations, or backups of important files. Most DVD writers can also read existing DVDs and CDs, making them versatile tools for accessing and sharing content. They are commonly found in computers, but standalone models are also available for home use, providing an easy way to create physical copies of digital media.