आप कैसे बता सकते हैं कि दो डीवीडी बिल्कुल वही हैं या नहीं?

I have two DVDs and if I open the them, then copy the contents to my hard-drive to compare the respective files, it shows no difference. As far as I know, DVDs also have some additional content (such as information saying if the DVD is bootable along with some formatting information I guess).

How can I also check this additional content? Is it possible without additional programs on Windows or Ubuntu?

The easiest way to determine if two discs are the same is to run a hash of both of them:

sudo md5sum /dev/cdrom

If the hashes match, then the disks are exactly the same. However, if the hashes do not match, then this will not tell you what is different about them. If even a single bit is different, you will get a totally different hash.

You can check the partition table of a disc with fdisk:

sudo fdisk -l /dev/cdrom

Just comparing folders and files misses other things about the disc. If you create an.ISO image file from each disc and byte compare them, you would have a better idea if the discs are really the same or not.