What is an ISBN, an ISSN, or a DOI?

These three things are unique identifiers:


International Standard Book Number - for books, and book-like resources, eg: eBooks, audiobooks, and graphic novels


International Standard Serial Number - for serial publications, or an ongoing resource, such as periodicals, magazines, journals, and comics.


Digital Object Identifier for an object, both physical and digital, large or small. It can apply to an article in an academic journal, an object in a museum, a recorded speech, or even a painting in an art gallery.