week two lecture
TRANSCRIPT
INFORMATION AND COMMUNICATION TECHNOLOGIES IN EDUCATION
Internet and its application
Learning ObjectivesThe learner must be able to:
1. Define internet2. Identify other networks3. Explain the world wide web4. Explain how to web create the web
Internet, the definitions• The Internet is a global system of
interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide.
• Internet, a system architecture that has revolutionized communications and methods of commerce by allowing various computer networks around the world to interconnect.
• However, a network is a cluster of computers, with one computer acting as a server to provide network services such as file transfer, e-mail, and document printing to the client computers or users of that network.
Internet, the definitions• The Internet is considered as network of
network• Using gateways and routers, a local area
network (LAN) can be connected to other LANs to form a wide area network (WAN).
• These LANs and WANs can also be connected to the Internet through a server that provides both the necessary software for the Internet and the physical data connection (usually a high-bandwidth telephone line, coaxial cable TV line, or wireless)
• The Internet carries an extensive range of information resources and services
• The Internet has no centralized governance in either technological implementation or policies for access and usage
Related Networking lexicons• Intranet• Extranet• Ethernet
Internet ServicesService
Purpose
ftp For transferring files between computers; can be anonymous or password protected (from File Transfer Protocol)
gopher
For menus of material available on the Internet (seldom used)
http For posting and reading documents (from the Hypertext Transfer Protocol used by the World Wide Web)
https For posting and reading encrypted (secure) documentsimap For receiving electronic mail (from Internet Message Access
Protocol)irc For real-time text messaging (from Internet Relay Chat)mud For real-time game playing (from MultiUser Dimension)pop For receiving electronic mail (from Post Office Protocol)rtsp For streaming media control (from Real Time Streaming Protocol)telnet For logging on and working from remote computerssmtp For sending mail (Simple Mail Transport Protocol)usenet For participating in discussion groups (from USERS NETwork)
Internet Services• Each Internet service is implemented on an
Internet server by dedicated software known as a daemon. (Actually, daemons only exist on Unix/Linux systems—on other systems, such as Windows, the services may run as regular applications or background processes.)
• Daemons are agent programs that run in the background, waiting to act on requests from the outside. In the case of the Internet, daemons support protocols.
History of the Internet• The Internet began as a research network
funded by the Advanced Research Projects Agency (ARPA) of the U.S. Defense Department, when the first node of the ARPANET was installed at the University of California at Los Angeles in September 1969.
• By the mid-1970s, the ARPANET “inter-network” embraced more than 30 universities, military sites, and government contractors, and its user base expanded to include the larger computer science research community.
History of the Internet• In 1989, responsibility and management for the
ARPANET was officially passed from military interests to the academically oriented NSF, and research organizations and universities (professors and students alike)
• Commercial and business use of the Internet was not permitted until 1992, but businesses have since become its driving force.
How the Internet Spread• Three inventions that spread the use of the Internet
were:• The personal computer (early 1980s)• The World Wide Web (1989)• The browser (1991)
The World Wide Web (www), definition• The World Wide Web (abbreviated as WWW or
W3, commonly known as the Web), is a system of interlinked hypertext documents (HTML doc) accessed via the Internet.
• Also seen as a wide-area hypermedia information initiative aiming at providing universal access to a large universe of information
Differences between the Internet and Web• The Internet and the WWW are not synonymous
How is information accessed on the Web• In its simplest expatiation
How is information accessed on the WebIn order to connect to the Internet you must have:• A modem: allows your computer to send
and receive signals through telephone lines• An Internet service provider (ISP):
required for all home connections• Browser software: might need plug-in
programs to retrieve some types of media applications
How is information accessed on the Web (Connecting to the Internet)
Modem (modulator-demodulator)• External Modem: This is a modem separated from
the system unit in the computer case. It is connected to the serial port of the computer by means of a cable. It is connected to the telephone wall jack by another cable.
• Internal Modem: An internal modem is a circuit board (a modem card) that can be added to the system unit of the computer. It takes one of the expansion slots.
How is information accessed on the Web (Connecting to the Internet)
An Internet service provider (ISP) or Internet access provider (IAP): ISPs employ a range of technologies to enable consumers to connect to their network through:• Dial-up• DSL (Digital Subscriber Line),• ADSL (typically Asymmetric Digital Subscriber Line)• Broadband wireless,• Cable modem,• Fiber to the premises (FTTH)
How is information accessed on the Web• What transpires on the Internet
How is information accessed on the Web (Connecting to the Internet)
Browser software (See below for further explanation):Is a software application for retrieving, and presentinginformation resources on the Wsorld Wide Web.Information the web is identified or located by Uniform Resources Identifier (URI) or Uniform Resource Locator (URL)Early browsers:• Mosaic = 1993 by• Nescape Navigator = 1994• Internet explorer = 1995
Web Browser, definition• Web browsers are information-rendering
software applications• software application for retrieving, presenting
and traversing information resources on the World Wide Web
• used to access information provided by web servers in private networks or files in file systems.
• Early browsers included WorldWideWeb (Nexus), Mosaic (Netscape) and Netscape Navigator
• Examples of popular web browsers include Google Chrome, Firefox, Internet Explorer (IE), Safari and Opera
Navigating the WebIn order to work with multimedia on the Internet, you must understand:• The browser screen and its standard
elements• URL addresses and the information they
contain
Features of Web Browsers
Dropdown Menu Tab Display
Address Bar
Search Bar with Search Engine
Refresh Button which doubles as Cancel button
Hit Display Area
Bookmarks Toolbar
Backward Button
Features of Web Browsers
Address Bar doubling as Search Bar ForwardButton
BackwardButton
Dropdown Menu
Features of URL / URI
https://www.schoology.com/assignments/index.html
Uniform Resource Locator / Uniform Resource Identifier
https://www.schoology.com/This address is an internet serve that uses hypertext transfer protocol
This represent the internet service know as World Wide Web
This belongs to a company calledSchoology. It is technically describedAs Domain Name
Surfing with Web Search Engine• Information resource gateway for surfing
information online• It is designed to search for information
on the World Wide Web.• Search results are referred to as Search
Engine Results Page (SERP) • SERP contain Hits populated on the
browser’s display pages• Hits = targets + source / Destination
Examples of Web Search EngineYahoo, Google, Bing, Yandex, AOL, Daemon, Baidu and Ask
Web Resource (Website)• Website is a set of related webpages
containing multimedia types and hosted on a server with a single domain name
• Webpage is an information resource, or specifically an HTML document suitable for the World Wide Web and can be accessed through a web browser
Form of Website• Static website (flat page): contains static
webpages and are delivered to the user exactly as stored (interaction takes place at client side)
• Dynamic website: contains active or dynamic pages, self automated and can customize it content based client interaction (dynamic code and dynamic content)
• Rich Internet Applications: desktop app with rich user experience. Web application that has many of the characteristics of desktop application software
Taxonomy of Website• Blog (weblog)• Electronic Commerce (e-commerce)• Gripe site• Gallery site• Dating Site• Phishing Site• Warez and Torrent Site• Question and Answer sites
Building a WebsiteTo build a website – dynamic or static- the developer must understand any of these fundamental scripting languages.HTML – Hypertext Markup Language: popular structural semantic language for structuring webpages. HTML 5 is the latestSGML – Standard General Markup Language DHTML – Dynamic Hypertext Markup LanguageXML – Extensible Markup Language XHTML – Extensible Hypertext Markup LanguageMXML – Macromedia Extensible Markup Language
Client/Server Architecture ( N-Tier)
Building a Website (client/server scripting language)
Client-side languages• HTML, CSS, JavaScript and AJAX Server-side language• PHP, Perl, ASP, Cold Fusion, Ruby on rail, JSP and
PythonDatabases (Relational Database Management System)• MySQL, NoSQL, Sybase, Oracle, MSSQL,Web Server Software• A web server (sometimes called an HTTP server or
application server) is a program that serves content using the HTTP protocol. E.g. Internet Information Service (IIS), Apache, Nginx, Lighttpd etc.
Building a Website (cont’d)
Tool for developing websites• Simple text editors• WYSIWYG offline editors• WYSIWYG online editors• Template-based editors
Deploying a Website (cont’d)• Websites are deployed on to a server for
world wide access
• Dedicated server, shared server or virtual server
• Buy domain name and server space ( monthly / yearly subscription) for a hosting service provider
• hosting service provider eg. GoDaddy, Hostgator, Google, Yahoo, aspspider etc.
Evolution of the WWW• Four altered evolutions emanating from
the web x.0 concept
Web 1.0• Publishing web or the info-centric web• Focused on primarily building the web,
making it accessible to the web client and commercializing the web for the first time
• Email communication was most effective
Web 2.0• Publishing web or people-centric web• Focused on participation, interaction and
collaboration• Application platform + personal computer
for communication• blogs, wikis, social networks, and RSS
feeds are web services that has brought about technical and social revolution
Web 3.0• Semantic web or Machine-centric web• Focused on connecting knowledge and
application• universal computing grid replacing
operating system and hard drive, resulting in large and dynamic groups of machines connected to each other.
• Web 3.0 is a convergence of several new technologies and service
Web 4.0• Intelligent web or Smart web or Agent-
centric web• Combines the power of human and
machine• enables the software agent(s) to reason
and communicate with other agents and systems and work collaboratively to accomplish things on user’s behalf (Agent-Centric)
Searching the Web
Use search engines to find the right Web page:• Create search queries that include
keywords.• Use Boolean search strategies to narrow
your search.• Use the right search engine to conduct
faster, more efficient searches.