Blu Ray Or Upconverting Dvd Is There Any Difference Between Blu Ray And 1080p Upconverter Dvd Players When Using Regular Dvds On 720p Tv?

Is there any difference between blu ray and 1080p upconverter dvd players when using regular dvds on 720p tv? - blu ray or upconverting dvd

I have a 720p plasma and I will not pay for all Blu-ray that I / we already have. This will be an upscaling DVD player to view movies in 720p not convert regular DVD and Blu-ray upconversion in the same. Or is that Blu-ray is the standard definition DVD?