The Internet & World Wide Web

The Internet Network - Collection of computing devices connected together to share resources Internet – Global network of networks enabling people to communicate, collaborate and share information and resources. World Wide Web – Multimedia portion of the Internet.

History of the Internet Late 1960’s – DOD’s ARPANET (Advanced Research Project Agency Network ) 1980’s – NSF’s CSnet (connecting all US universities) Domain Name System established Early 1990’s - World Wide Web Graphical browser By 2000 – Extensive global use p. 69

Applications of the Internet Communication – email and chatting / messaging Browsing / research – accessing the Web E-commerce – buying, selling and trading online Other – telephony, newsgroups, ftp, etc.

How the Internet Works Internet backbone (physical infrastructure) Protocols (standard language) Ensure that devices communicate in a uniform and manageable manner Internet backbone (physical infrastructure) Consists of national and international communication networks Internet service providers (ISP) Provide users with physical connection/access to the Internet Provide other services such as email, web hosting

How the Internet Works Protocols for the Internet Internet Transmission Control Protocol (TCP) Internet Protocol (IP) Hypertext Transfer Protocol (HTTP) File Transfer Protocol (FTP) Internet A packet switching network Client/server Client makes a service request Server provides the service

How the Internet Works IP address – numeric address identifying a computer / device on the Internet Domain name – text based name for an IP address (Shelly, Cashman & Vermaat, 2008)

The World Wide Web World Wide Web – Multimedia portion of the Internet. Comprised of text, graphics audio and video. A worldwide collection of electronic documents. Each electronic document is called a Web page. A Web site is a collection of related Web pages. Web pages stored on a Web server. URL (Uniform Resource Locator) - Unique address for a Web page A web server delivers the Web page to your computer p. 54

The World Wide Web Web browser - Program that allows you to view and interact with Web page Internet Explorer FireFox Chrome Safari p. 54

The World Wide Web Hyperlink - Connection to other related Web pages Elsewhere on same Web page Different Web page on same Web site Web page at a differentWeb site (Shelly, Cashman & Vermaat, 2008) p. 57

The World Wide Web Plugin -Programs that extend the capability of a browser You can download many plug-ins at no cost from various Web sites (Shelly, Cashman & Vermaat, 2008)

Communication via the Internet Communication - number one use / application of Internet Asynchronous communication (email) Not real time (not at same time) Participants can leave messages to be responded to at recipient’s convenience Synchronous communication (chat) People communicate in real time Participants must be engaged in communication at the same time

E-mail E-mail address - Unique name that consists of a user name and domain name that identifies the user jane_doe@students.towson.edu.us User name: jane_doe Sub domain: students Domain name: towson Domain root/type: .edu Country extension (optional): .us p. 94 Fig. 2-27

Intranet, Extranet & VPN Intranet - internal corporate network built using Internet and World Wide Web standards and technologies Extranet - network that links selected resources of the intranet of a company with external customers, suppliers, or other business partners. VPN (Virtual private network) – a secure connection between two points on the Internet

References Shelly, G., Cashman, T. & Vermaat, M. (2008). Discovering computers. Fundamentals, 4th edition. Thomson: Course Technology.