Understanding a DOI is important when doing specific research. It is a unique code for each article that is like a fingerprint for that article. The DOI acts as a barcode to identify articles online.
The Publication Identifier is a unique identifier used by publishers of a number of scientific journals, books, magazines, newspapers, serials, scientific blogs and databases to find information on that special written product using a set of codes.
The identifying tag assigned for each separate edition and variation (except reprintings) of a publication is called “publication identifier” that helps in finding information on an article or publication using a set of codes.