The technology used to record information has significantly changed over time.   Photos moved from glass plates negatives, to nitrate negatives and now are primarily digital.  Similar evolutions have surrounded the production of audio and video recordings.  Even a paper original can be lost in fires or floods.  Digital copies can be stored in many places at once making that a safer option. (Lots of Copies Keeps Stuff Safe)

Digitizing audio, video and text requires special equipment and expertise and additional precautions may have to be taken depending on the condition of the original.  By identifying the type and condition of historic material we can identify and prioritize  necessary expertise, technology and funding.