Digital amnesia is a phenomenon in which technological knowledge becomes lost to humanity through constant technological advancement. When a digital source can no longer be read due to the unavailability of the reader required to read the media, hardware, software or physical media, or even if the media itself is damaged beyond repair, digital amnesia is said to have occurred.
This is also known as digital obsolescence.
Techopedia explains Digital Amnesia
The continuous progress and evolution of technology in terms of hardware, software, operating systems and methods of digital encoding guarantees the possibility that digital amnesia will become a problem in the near future. There are many versions of programs and applications that have been considered as a standard for some time, but in the end they will always be replaced by newer versions with upgraded functions. The files that are meant to be edited or read by an old program will become unreadable if used with newer programs.
As more versions and innovative ideas develop, old versions of programs created by a company will become obsolete because they cannot be used with the new system. For example, Microsoft Works versions that are below 4.5 cannot run on Windows 2000 or later. There are even programs that are currently in mainstream use that will not work properly on Windows 7 machines; compatibility mode needs to be enabled in order for them to work. Making a new program backward-compatible with older file formats is one way of avoiding this problem.