When a TV show never gets an official DVD release.
Someone usually collects a complete TV series from video tape recordings or official VHS release and makes a DVD for sale, either on eBay or iOffer.
Movie Basement DVD:
When a movie is never given an official DVD release.
Someone often creates a DVD from an existing VHS release of an obscure Cut favorite that has yet to have an official DVD release
2.) George Lucas will never release the Star Wars Holiday Special so your best bet is to find a Basement DVD of it.