A DVD (Digital Versatile Disc) is primarily a type of optical storage medium. DVDs are capable of storing large amounts of data, including video, audio, and software. They typically hold around 4.7 GB of data for single-layer discs and up to 8.5 GB for dual-layer discs. DVDs are widely used for distributing films, software applications, and backup storage. They rely on laser technology to read and write data, making them a popular choice before the rise of digital downloads and streaming services.