Internet

=== Communication ===
[[Email]] is an important communications service available via the Internet. The concept of sending electronic text messages between parties, analogous to mailing letters or memos, predates the creation of the Internet.<ref>{{cite journal|first=Ron|last=Brown|title=Fax invades the mail market|url=https://books.google.com/books?id=Ry64sjvOmLkC&pg=PA218|journal=New Scientist|volume=56|issue=817|date=October 26, 1972|pages=218–221}}</ref><ref>{{cite journal|first=Herbert P.|last=Luckett|title=What's News: Electronic-mail delivery gets started|url=https://books.google.com/books?id=cKSqa8u3EIoC&pg=PA85|journal=Popular Science|volume=202|issue=3|date=March 1973|page=85}}</ref> Pictures, documents, and other files are sent as [[email attachment]]s. Email messages can be [[Carbon copy|cc-ed]] to multiple [[email address]]es.

[[Internet telephony]] is a common communications service realized with the Internet. The name of the principal internetworking protocol, the Internet Protocol, lends its name to [[voice over Internet Protocol]] (VoIP). The idea began in the early 1990s with [[walkie-talkie]]-like voice applications for personal computers. VoIP systems now dominate many markets and are as easy to use and as convenient as a traditional telephone. The benefit has been substantial cost savings over traditional telephone calls, especially over long distances. [[Cable modem|Cable]], [[ADSL]], and [[mobile data]] networks provide [[Internet access]] in customer premises<ref name=EBSCOhost>{{cite journal|last=Booth|first=C|title=Chapter 2: IP Phones, Software VoIP, and Integrated and Mobile VoIP|journal=Library Technology Reports|year=2010|volume=46|issue=5|pages=11–19}}</ref> and inexpensive VoIP network adapters provide the connection for traditional analog telephone sets. The voice quality of VoIP often exceeds that of traditional calls. Remaining problems for VoIP include the situation that emergency services may not be universally available and that devices rely on a local power supply, while older traditional phones are powered from the local loop, and typically operate during a power failure.