A simple VHS camera will record at 200 lines, SVHS at 400. A DV camera can record a the equivalent of over 800 lines. The more lines, the better the picture, and more importantly, the more information to use in editing. The fewer the lines, the more is lost each time you recopy or edit. The pictures above demonstrates the quality degradation of a third generation video.
Third generation means the video was copied in the editing process, then copied once again.
For VHS and 8 mm a third generation tape is unusable. SVHS and High 8 allow greater flexibility and have nearly twice the standard resolution. Digital Video allows the possibility for unlimited editing and saving of video clips and sequences. With digital, however, storage becomes an issue. Digital still cameras have been an alternative input device for some years.