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Definition: URI


(Uniform Resource Identifier) The addressing technology for identifying resources on the Internet (or private intranet). The URI that is most widely known is the URL, which is the address of a Web page and technically an "HTTP URI." However, the Internet serves many functions (see below). See HTTP, URL and URN.

There are more than 200 historical, permanent and provisional URI types, known as "schemes." Following are some of the major ones. For details, visit www.iana.org/assignments/uri-schemes.

 URI SCHEME

 Prefix   To gain access to

 http:    Web server
 https:   secure Web server
 ftp:     file server
 im:      instant messaging
 itms:    iTunes streaming

 news:    Usenet newsgroups
 nntp:    Usenet newsgroups

 mailto:  send email (SMTP)
 imap:    IMAP mailbox
 pop:     POP mailbox

 sip:     voice over IP (VoIP)
 sips:    secure VoIP
 h323:    H.323 videoconference

 ldap:    directory request
 telnet:  run program

 nfs:     network file system
 wais:    WAIS server
 gopher:  Gopher server

 file:    local file on host