“Saying a BluRay is not a DVD is like saying VHS is not a video tape.”
No, it is not. VHS is a format of video tape. It is not the only format of video tape. Betamax is also video tape, but not the same format at VHS. Likewise, while BluRay and DVD formats are both discs with digital recordings, they are *not* the same format - just as HDDVD is not the same format as either one of them. MACs are not PCs, either...though they are both types of computers.
“Likewise, while BluRay and DVD formats are both discs with digital recordings, they are *not* the same format “
A DVD is physical medium as is the tape. Not a format. BluRay is the format encoded on the disk.
Just like VHS format is encoded on a tape.