What is Netflix DVD

There are SEVERAL services out there now other than Netflix if you are looking for a movies that you don't see on Netflix. I highly suggest a Smart TV with apps on it already. Amazon Prime is one kind of service with Netflix does not have it. Sometime Hulu Plus is another.

Netflix DVD is a DVD postal rental service. You pick it they post it , you watch it then post it back

Not every program is available for streaming, nor is every movie. Netflix is able to strike a deal with some movie studios and television content providers to make their movies or shows available for streaming.
For other content, you have to rely on viewing the DVD/Blu-Ray discs available through the Netflix disc service, which costs an additional charge each month. Then you can create a list of discs to be delivered to you in sequence (watch it, return it, get the next disc).
As you browse the Netflix list of programs/movies, you will see a 'Play' button if the content is available for streaming. If you don't see the 'Play' button, you have to watch the disc version.
If you don't want to add the disc service to your Netflix account, you can always use Redbox, which *MAY* have the program/movie you want to watch on disc.