Internationalized resource identifier (IRI) is a standardization of uniform resource identifier (URI) used to identify web resources worldwide. However, there are several synonyms that can substitute for IRI. Uniform resource name (URN) is a type of URI that identifies the resource by name and only stays valid while the resource exists. The uniform resource locator (URL) identifies web resources by location and specifies the method to access them. The relative uniform resource locator (rURL) specifies the URL's location relative to the current webpage being accessed. Lastly, the internationalized domain name (IDN) system offers domain names that include characters outside of the English alphabet, permitting domain names to be written in the native language of the user.