Definition:
IRI is an abbreviation that stands for Internationalized Resource Identifier. An IRI is a sequence of characters from the Universal Character Set (Unicode). An IRI is intended to replace URIs for identifying resources. However, in the case of resource retrieval, IRIs are mapped to URIs for backwards compatibility and because most user agents can only retrieve URIs. IRIs are defined in RFC 3987.
Examples:
IRIs are written: scheme : path similar to URIs. The primary difference is that you can use Unicode characters in an IRI, and you cannot in a URI.
Schemes include: file, http, ftp, news, mailto, gopher.
