DOIs, or Digital Object Identifiers, are used to identify content objects in the digital environment. They provide an actionable, interoperable, persistent link of an object, which can be any entity (thing: physical, digital, or abstract). DOIs, as defined by the International DOI Foundation, are:
DOIs mean that the same version of an article, image, dataset, graph, etc., can be retrieved at any point in future.
DOI = Digital Object Identifier
IDF = International DOI Foundation, the operating and governing organization: http://www.doi.org/
RAs = DOI Registration Agencies, which are members of IDF offering the system to customers who wish to assign DOI names
DOIs are structured as a unique alphanumeric string assigned to a digital object. In Data Planet, DOIs are assigned by the CrossRef RA and each DOI is associated with a set of basic metadata and a URL pointer so that it uniquely identifies the content item and provides a persistent link to its location on the internet.