High-efinition (HD) video generally refers to any video system of higher resolution than standard-definition (SD) video, most commonly at display resolutions of 1280×720 (720p) or 1920×1080 (1080i or 1080p). This article discusses the general concepts of high-definition video, as opposed to its specific applications in television broadcast (HDTV), video recording formats (HDCAM, HDCAM-SR, DVCPRO HD, D5 HD, XDCAM HD, HDV and AVCHD), the optical disc delivery system Blu-ray Disc and the video tape format D-VHS.