Is there a difference beween HD and BLUE RAY?

[SoapyEars]

I have several HD channels on my cable subscription. Does that mean they are Blu-ray or just HD? I assume Blu-ray is better than HD. Are the dvd's in my collection all HD? Or just the ones that say Blu-ray? Are dvd's that are not blu-ray just a step up from VHS or are they HD?

 

[Snackie]

HD is High definition, so it refers to the quality. blueray is the disc the movie comes on.
Bluray discs have a better picture and sound quality than dvds
so basically your bluray movies are in HD.