Editing Forward compatibility (section)

===Optical media===
Each of the three most common 12&nbsp;cm [[optical media]] formats ([[CD]], [[DVD]], and [[Blu-ray]]) was first released in read-only form years before writable forms were available.  Within each format, there is both forward and backward compatibility, in that most older read-only drives and players can read (but not write) writable media in the same format, while read/write drives can read (but not write) old read-only media.  There is no forward compatibility between formats; a CD player, for instance, can't read a DVD (a newer format), not even the audio tracks.  There may be backward compatibility for better marketability (such as a DVD player playing an audio CD), but it is not intrinsic to the standards.<ref>
{{cite web|url=http://www.blu-raydisc.com/en/Technical/FAQs/Blu-rayDiscFormat.html|title=Can Blu-ray Disc products play DVD and CD?|access-date=January 25, 2009|archive-url=https://web.archive.org/web/20090218032036/http://www.blu-raydisc.com/en/Technical/FAQs/Blu-rayDiscFormat.html|archive-date=February 18, 2009|url-status=live|df=mdy-all}}
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