WWW
From CIRCA
| VTracker |
|---|
| Content stucture deleted. (1 Occurances) |
| Content structure inserted. (1 Occurances) |
| Content changed. (2 Occurances) |
Based on a presentation by Michael Burden
October 14 2010
WWW is the World Wide Web. It is an internet service allowing navigation between interlinked hypertext and hypermedia documents.
Contents |
Development of the idea of the WWW
The steampunk web
In 1934, [Paul] Otlet sketched out plans for a global network of computers (or ???electric telescopes,??? as he called them) that would allow people to search and browse through millions of interlinked documents, images, audio and video files. He described how people would use the devices to send messages to one another, share files and even congregate in online social networks. He called the whole thing a ???r??seau,??? which might be translated as ???network??? ??? or arguably, ???web.???
Alex Wright, "The Web Time Forgot," New York Times(June 17, 2008).
The world's knowledge was growning too large and Otlet was trying to find a way for people to search through the enormous and scattered volumes of printed and published material available, and to access its contents.By 1895 he was collecting data on every book ever published, along with many other media forms, including photographs, pamphlets, posters, and magazines. Around 1915 he had established a service that allowed customers to send a request for information via telegram or mail.
Hypertext
An earlier attempt at access to all the world's knowledge was the publication of encyclopedias in the 18th century. The most famous early encyclopedia was lead by Denis Diderot, and modelled on an earlier English Cyclopedia by Ephraim Chambers, published in 1728. One of its innovations was cross-referencing between similar articles.
In 1945 Vannevar Bush described the Memex in an article in the Atlantic Monthly. It was a personal mechanical library, containing any records a person chose to store. Each stored document would receive a numerical code, for easy retrieval. Users could create associative trails of links between documents.
Digital systems are particularly suited to non-sequential navigation of information, so innovation in navigation grew with technological development.
In 1968 Ted Nelson coined the term hypertext to refer to a portion of text that is not only related to another text, but also allows immediate access to the related text. Douglas Engelbart gave the first public demonstration of a hypertext system that year. In 1987 Apple released a hypertext application named HyperCard.
The function of the World Wide Web
HyperText is a way to link and access information of various kinds as a web of nodes in which the user can browse at will. Potentially, HyperText provides a single user-interface to many large classes of stored information such as reports, notes, data-bases, computer documentation and on-line systems help. We propose the implementation of a simple scheme to incorporate several different servers of machine-stored information already available at CERN, including an analysis of the requirements for information access needs by experiments.
Abstract to "WorldWideWeb: Proposal for a hypertexts Project". Berners-Lee, Tim; Cailliau, Robert (November 12, 1990). Retrieved October 13, 2010.
Technology of the WWW
The TCP/IP protocol suite
The internet and other global networks are possible through a stack of layered protocols
- 'Link layer' - the protocols for exchanging packets of data along a link between two nodes
- 'Network layer (IP)'- the protocols for transporting packets from a host node to a destination node
- 'Transport layer (TCP)' - end-to-end communication services for applications across a network
- 'Application layer' - any protocol or method enabling process-to-process communication
The World Wide Web is located in the Application layer. Other services and applications in this layer include:
- BitTorrent (peer-to-peer file exchange)
- Internet Relay Chat or IRC (text messaging)
- Voice over IP or VoIP (telephony)
- Simple Mail Transfer Protocol or SMTP (email, typically sending)
- Internet Message Access Protocol or IMAP, and Post Office Protocol or POP (email retrieval)
Protocols, standards and methods of the Web
- Uniform Resource Identifier or URI is a string that identifies
a name or resource on the Internet.
- domain names are identification labels
- top-level domains are the highest level in the Domain Name System (DNS) hierarchy and include .ca, .com, .net, .fr
- HyperText Transport Protocol or HTTP is the means of sending and retrieving hypermedia documents across the internet.
- HyperText Markup Language or HTML develops from SGML (but with a hypertext tag).
- Cascading Style Sheets or CSS is a protocol for display of HTML documents.
- Scalable Vector Graphics or SVG enables display of two-dimensional graphics
- PNG's not GIF or PNG is a method for encoding an image
