The picture quality of the DVD disc is consistent from the first play to the thousandth play. Plus, DVD discs will not deteriorate over time, are unaffected by magnetic fields (which can literally erase a VHS cassette) and do not require rewinding after viewing.
DVD discs are the same diameter (120mm) and thickness (1.2mm) as a Compact Disc, but that is where the similarities end. A single DVD disc has the capability to store up to 13 times the data contained on a CD, on one side! If you factor in DVD's capability to utilize both sides of a disc for data storage, you have an information marvel that offers 26 times the power of a Compact Disc!
That enhanced capability is a tremendous enabling device. DVD will revolutionize Multimedia, information retrieval and storage and mobile navigation. DVD will create new high quality audio standards, impact learning and training videos, and bring the Cinema experience to Home Entertainment.
For the reasons above and many more, DVDs are becoming the mainstream, and VHS is becoming obsolete.
Videotapes deteriorate faster than any other media. They are made of a magnetic imaging material a binder and a base. The videotape was never meant to be a long-term storage media. Due solely to the weakening of the binder, which holds the magnetic particles containing the video data to the plastic tape material, videotapes continually release their magnetic information particles over time until eventually the tape is unplayable. Environmental conditions can speed the process, but nothing is going to stop it. Equally as bad, simply playing a videotape causes some wear. The older the tape is the more deterioration will take place each time it's played, because the older binder material is weaker and therefore more particles are ripped away each time it's rubbed by the spinning player heads. Magnetic media's sensitivity to static shock or common electric fields further confirms it is a shortfall of magnetic storage media. All or some of the information stored on videotape can be wiped out by a simple static shock or an electric field from a household device as common as a VCR, stereo, speaker or TV.
Depending on the conditions of storage, usage and the equipment used to play the video, it will have a life of between a few years and about 15 or 20 years. Lower end analog formats such as VHS and Video8 degrade even faster.