Dual-layer DVD-R technology provides the ability to record up to 8.5 GB of data on a single disc surface. This nearly doubles the standard DVD capacity of 4.7 GB. That means one side of a DVD-R disc will hold up to four hours of DVD quality video or 16 hours of VHS quality video. Dual-layer discs can also be read on DVD players that were originally designed for single-layer discs.