DVD (Digital Versatile Disc, formerly Digital Video Disc) is an optical disc storage format. DVDs can be single- or double-sided, and each side can be single- or dual-layer recorded. A variant of MPEG-2 encoding is used for video streams, which results in Packetized Elementary Stream packets containing the data (including subsidiary items such as subtitles).
DVDs overtook VHS tapes as the dominant format for video sales and rentals in the 2000s. The HD-DVD and Blu-ray Disc formats dueled it out in a format war to be the successor of the DVD, with BluRay ultimately winning, but DVDs are still widely used alongside them. Digital video formats (download or streaming) are increasing in popularity as a competitor to physical media.