Ontology

=Introduction= The hierarchical structuring of knowledge about things by subcategorising them according to their essential (or at least relevant and/or cognitive) qualities. Ontologies are very important for Digital Preservation as it makes objects and their relations to other objects easier to describe. A very simple, non exhaustive, example of a software object:
 * -> Thing
 * -> Computer
 * -> Hardware
 * -> Operating System
 * -> Software

Computer relates to Hardware, and Hardware has objects like CPU Architecture, Disk, Videocard, etc. Operating Systems could relate to a certain CPU Architecture, which relates back to Hardware. Software can -most of the time- only run on a specific Operating System, which can only run on a certain CPU Architecture, which relates back to a certain type of Hardware. =Related=
 * PUID
 * Planets Core Registry
 * Planets project Ontology

=References=
 * http://dictionary.reference.com/browse/ontology