Internet

=== Data transfer ===
[[File sharing]] is an example of transferring large amounts of data across the Internet. A [[computer file]] can be emailed to customers, colleagues and friends as an attachment. It can be uploaded to a website or [[File Transfer Protocol]] (FTP) server for easy download by others. It can be put into a "shared location" or onto a [[file server]] for instant use by colleagues. The load of bulk downloads to many users can be eased by the use of "[[Web mirror|mirror]]" servers or [[peer-to-peer]] networks. In any of these cases, access to the file may be controlled by user [[authentication]], the transit of the file over the Internet may be obscured by [[encryption]], and money may change hands for access to the file. The price can be paid by the remote charging of funds from, for example, a credit card whose details are also passed—usually fully encrypted—across the Internet. The origin and authenticity of the file received may be checked by [[digital signature]]s or by [[MD5]] or other message digests. These simple features of the Internet, over a worldwide basis, are changing the production, sale, and distribution of anything that can be reduced to a computer file for transmission. This includes all manner of print publications, software products, news, music, film, video, photography, graphics and the other arts. This in turn has caused seismic shifts in each of the existing industries that previously controlled the production and distribution of these products.

[[Streaming media]] is the real-time delivery of digital media for immediate consumption or enjoyment by end users. Many radio and television broadcasters provide Internet feeds of their live audio and video productions. They may also allow time-shift viewing or listening such as Preview, Classic Clips and Listen Again features. These providers have been joined by a range of pure Internet "broadcasters" who never had on-air licenses. This means that an Internet-connected device, such as a computer or something more specific, can be used to access online media in much the same way as was previously possible only with a television or radio receiver. The range of available types of content is much wider, from specialized technical [[webcast]]s to on-demand popular multimedia services. [[Podcast]]ing is a variation on this theme, where—usually audio—material is downloaded and played back on a computer or shifted to a [[portable media player]] to be listened to on the move. These techniques using simple equipment allow anybody, with little censorship or licensing control, to broadcast audio-visual material worldwide.

Digital media streaming increases the demand for network bandwidth. For example, standard image quality needs 1 Mbit/s link speed for SD 480p, HD 720p quality requires 2.5 Mbit/s, and the top-of-the-line HDX quality needs 4.5 Mbit/s for 1080p.<ref>{{cite web |last=Morrison |first=Geoff |url=http://www.nbcnews.com/id/40241749 |title=What to know before buying a 'connected' TV – Technology & science – Tech and gadgets – Tech Holiday Guide |publisher=NBC News |date=18 November 2010 |access-date=8 August 2011 |archive-url=https://web.archive.org/web/20200212091603/http://www.nbcnews.com/id/40241749 |archive-date=12 February 2020 |url-status=live }}</ref>

[[Webcam]]s are a low-cost extension of this phenomenon. While some webcams can give full-frame-rate video, the picture either is usually small or updates slowly. Internet users can watch animals around an African waterhole, ships in the [[Panama Canal]], traffic at a local roundabout or monitor their own premises, live and in real time. Video [[chat rooms]] and [[video conferencing]] are also popular with many uses being found for personal webcams, with and without two-way sound. YouTube was founded on 15 February 2005 and is now the leading website for free streaming video with more than two billion users.<ref>{{Cite web|title=Press|url=https://www.youtube.com/about/press/|access-date=19 August 2020|website=YouTube|archive-date=11 November 2017|archive-url=https://web.archive.org/web/20171111094352/https://www.youtube.com/yt/about/press/|url-status=live}}</ref> It uses an HTML5 based web player by default to stream and show video files.<ref>{{Cite news|url=https://youtube-eng.googleblog.com/2015/01/youtube-now-defaults-to-html5_27.html|title=YouTube now defaults to HTML5|work=YouTube Engineering and Developers Blog|access-date=10 September 2018|language=en-US|archive-url=https://web.archive.org/web/20180910204225/https://youtube-eng.googleblog.com/2015/01/youtube-now-defaults-to-html5_27.html|archive-date=10 September 2018|url-status=live}}</ref> Registered users may upload an unlimited amount of video and build their own personal profile. [[YouTube]] claims that its users watch hundreds of millions, and upload hundreds of thousands of videos daily.