Answered By: Steven Profit Last Updated: Apr 27, 2016 Views: 157
The individual number or serial designation identifying specifically any of the items, as books or records, acquired by a library, collection, or the like. (from http://www.dictionary.com/browse/accession-number).
Generally speaking, the accession number isn't very helpful to library users wanting to find library materials. More helpful are call numbers for hardcopy items and digital object identifier (doi) for electronic items like journal articles.