URI (Uniform Resource Identifier)

URI (Uniform Resource Identifier) is an identifier consisting of a sequence of characters matching the syntax rule that is named &lt;URI&gt; in RFC 3986. It enables uniform identification of resources via a set of naming schemes. A URI can be further classified as a locator, a name, or both. The term &quot;Uniform Resource Locator&quot; (URL) refers to the subset of URIs that, in addition to identifying a resource, provides a means of locating the resource by describing its primary access mechanism (e.g., its network &quot;location&quot;). The term &quot;Uniform Resource Name&quot; (URN) has been used historically to refer to both URIs under the &quot;urn&quot; scheme [RFC2141], which are required to remain globally unique and persistent even when the resource ceases to exist or becomes unavailable, and to any other URI with the properties of a name. An example of a URI that is neither a URL nor a URN is sip:psap@example.com.

URL (Uniform Resource Locator)

A type of URI, specifically used for describing and navigating to a resource (e.g., https://www.nena.org)

URN (Uniform Resource Name)

A type of URI. Uniform Resource Names (URNs) are intended to serve as persistent, location-independent, resource identifiers and are designed to make it easy to map other namespaces (which share the properties of URNs) into URN-space. An example of a URN is urn:service:sos.


 * NENA-STA-010, NENA i3 Standard for Next Generation 9-1-1
 * NENA-STA-006, NENA Standard for NG9-1-1 GIS Data Model


 * RFC 3986, Uniform Resource Identifier (URI): Generic Syntax
 * RFC 8141, Uniform Resource Names (URNs)