The purpose of keeping archives is to collect, preserve, and make available records of enduring value to the public. Records are kept for their usefulness to society, and tend to have one or more of the following:
Enduring value means the items are worthy of permanent (insofar as it is possible) preservation. Sometimes it is the only the content that needs to be preserved, which can be transferred to another medium. Sometimes archives contain records with intrinsic value.
Intrinsic value refers to qualities of an item that make it necessary to keep the original, even when copies exist.
Possible characteristics of records that have intrinsic value:
For records that are not 'born digital,' creating accessible digital versions of original records requires a lot of time and effort. Find out what goes into making records available online at the National Archives and Records Administration.
Explore collections of archival materials freely available online.
Boston University Primary Source Guide
More information on primary sources and archival collections available online.