A standard DVD-R blank disc holds approximately two hours of video. If, however, you want to put more than two hours on a single DVD-R disc, you can use compression software which allows you to burn more digital information onto a single disc. Compression software works by lowering the quality of the video. Since lower quality video requires less storage capacity, you can fit more than two hours of compressed video on a blank DVD-R disc. Writer Bio

How to Burn More Than Two Hours on a DVD R - 91