..the Web provides a general form of identifier, called the Uniform Resource Identifier (URI), for identifying (naming) resources on the Web. Unlike URLs, URIs are not limited to identifying things that have network locations, or use other computer access mechanisms. A number of different URI schemes (URI forms) have been already been developed, and are being used, for various purposes. Examples include:

• http: (Hypertext Transfer Protocol, for Web pages) mailto: (email addresses), e.g.,
• mailto:em@w3.org
• ftp: (File Transfer Protocol)
• urn: (Uniform Resource Names, intended to be persistent location-independent resource identifiers), e.g., urn:isbn:0-520-02356-0 (for a book)

No one person or organization controls who makes URIs or how they can be used. While some URI schemes, such as URL's http:, depend on centralized systems such as DNS, other schemes, such as freenet:, are completely decentralized. This means that, as with any other kind of name, no one needs special authority or permission to create a URI for something. Also, anyone can create URIs to refer to things they do not own, just as in ordinary language anyone can use whatever name they like for things they do not own.