1. Introduction to the Web
ARPANET
Beginning late 1960’s
Included about a dozen ARPA sponsored Universities
ARPA: Advanced Research Projects Agency (US Defense Dept.)
Goal was to provide a network of interconnected computers
Main intention was to provide access to remote computers to facilitate research
Operating at 56 Kbaud (56k bits/second)!
Conventional telephone communication at the time was 110 b/s
Unexpected consequence – (electronic mail)!

2. Network communication
Packet Switching
Divide message into discrete “packets”
Send then independently
Reassemble on the receiving end
Allowed for simultaneous transmissions by multiple users
No central control
“nodes” behave independently
Network can expand/contract as needed

3. Transmission Protocols
TCP (Transmission Control Protocol)
Developed for original ARPANET
Ensured messages were properly routed between sender and receiver within the network
IP (Internet Protocol)
more networks developed
IP invented to handle communication between networks
Combination is known as TCP/IP
Allows for a “network of networks”

4. Network Expansion Initial network use limited
Universities and research institutions
Later, it was expanded to military use
Eventually, the government opened it up to commercial use
Initially - resentment in academic community
But, it led to substantial investment, competition, and expansion by businesses
Increase in “bandwidth”

5. World Wide Web
Two inventions provided standardization for information sharing
Both in content formatting and transmission
Developed by Tim Berners-Lee of CERN (European Nuclear Research Organization)
HTML
HyperText Markup Language
Enables hyperlinked text documents
HTTP
HyperText Transfer Protocol
Communication protocol for sending info across the web
Mosaic (1993)
Web-browser led to explosive growth of web use
developed by University of Illinois - Marc Andressen (later developed Netscape)
Today: Firefox (Netscape), Chrome, IE/Edge, Safari, …

6. World Wide Web Consortium (W3C)
Founded by Time Berners-Lee in 1994
Developed nonproprietary, interoperable technologies for the WWW
Q: What is meant by nonproprietary????
Q: What is meant by interoperable???
Primary goal – make the web universally accessible
Also a standardization organization
Web technologies standardized by the W3C are called Recommendations
Some recommendations include HTML, XHTML, CSS and XML

7. Web Technology Web is client/server technology Client (web browser)
requests resources from web servers
Resource – any object retrieved from a web server, such as an XHTML document, image, video, audio, Database information, etc.
Web servers
Service the request
Use specialized software (apache, IIS)

8. Web 2.0 Term coined in 2003 by Dale Dougherty of O’Reilly Media
Refers to a shift in web usage towards more collaborative, community-based sites and usage
Prior usage was primarily information dissemination from businesses and other providers (Web 1.0)
Social networking sites, blogs, wikis, etc.
Facebook, Wikipedia, YouTube, Ebay, …
Involves the user – they create, organize, share, critique, update, etc. the content
The future: Semantic Web
Instead of just sending and reading data on the web, obtain meaning from the data (semantics)