No medium for recording expressions of human creativity, thought, and accomplishment is immune to damage and decay. In this regard, the long-term maintenance of digital data is no different from the challenge faced by cultural repositories for generations past.
Yet digital preservation presents its own unique challenges, arising from the basic nature of digital data—it is machine-readable, not eye-readable. Unlike the fairly straightforward process of decoding other machine-dependent media, such as microfilm or LPs, maintaining digital data in a form that is intelligible to humans involves the use of a complex set of tightly interwoven technologies. Numerous reports detail why digital preservation is so challenging—from technological obsolescence of hardware, software, and formats to media vulnerability, competing stakeholder interests, organizational and legal issues, and resource requirements. In this section, we map such challenges to the seven attributes of the merged model presented earlier.
As in the other sections of the tutorial, we highlight both organizational, technical, and resource challenges by these respective symbols 
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