Internet and Web Unit 4 PDF

Internet and Web UNIT 4 Template designed by the eLearning Unit @Kab  Objectives and expectations ▪ The objectives of this class on the internet and www are mainly: ▪ introduce the learners to internet, web, web based resources and how to make a...

Internet and Web UNIT 4 Template designed by the eLearning Unit @Kab  Objectives and expectations ▪ The objectives of this class on the internet and www are mainly: ▪ introduce the learners to internet, web, web based resources and how to make a quality search online. ▪ Expose how the www, and internet work and their importance. ▪ How to find information online and how to evaluate search results? ▪ How to make a search strategy? ▪ How to find information online? ▪ Explore communicating and collaborating online. ▪ Explain the various digital tools/ resources for collaboration available at your university 2  ▪ Refers to global computer network providing a variety of information and communication facilities, consisting of interconnected networks using standardized communication protocols. ▪ The popular term for the Internet is the Internet “information highway”. ▪ Rather than moving through geographical space, it moves your ideas and information through cyberspace – the space of electronic movement of ideas and information. 3  The uses of the Internet ▪ Send e-mail messages. ▪ Send (upload) or receive (down load) files between computers. ▪ Participate in discussion groups, such as mailing lists and newsgroups. ▪ Surfing the web. ▪ The use spans across domains : education, agriculture, etc. 4  ▪ The Web (World Wide Web) refers to information organized into Web pages containing text and graphic images. ▪ It contains hypertext links, or highlighted keywords and images that lead to related information. What is Web? ▪ A collection of linked Web pages that has a common theme or focus is called a Web site. ▪ The main page that all of the pages on a particular Web site are organized around and link back to is called the site’s home 5 page.  How to access the Internet?  Many institutions have direct access to the Internet using special high-speed communication lines and equipment. Employees can access it through the organization’s local area networks (LAN) or through their own personal computers.  Another way to access the Internet is through Internet Service Provider (ISP). 6  How to access the Internet? ▪ To access the Internet, an existing network need to pay a small registration fee and agree to certain standards based on the TCP/IP (Transmission Control Protocol/Internet Protocol) reference model. ▪ Each organization pays for its own networks and its own telephone bills, but those costs usually exist independent of the internet. ▪ The regional Internet companies route and forward all traffic, and the cost is still only that of a local telephone call. 7  ▪A commercial organization with permanent connection to the Internet that sells temporary connections to Internet Service Provider (ISP) subscribers. ▪ Examples: ▪ Telecom companies and many others. MTN, Airtel, etc. 8  How to access the web? ▪ Once you have your Internet connection, then you need special software called a browser to access the Web. ▪ Web browsers are used to connect you to remote computers, open and transfer files, display text and images. ▪ Web browsers are specialized programs. ▪ Examples of Web browser: Netscape Navigator (Navigator) and Internet Explorer. 9  ▪ Web is a collection of files that reside on computers, called Web servers, that are located all over the world and are connected to Client/Server each other through the Internet. Structure of the ▪ When you use your Internet connection to Web become part of the Web, your computer becomes a Web client in a worldwide client/server network. ▪ A Web browser is the software that you run on your computer to make it work as a web client. 10  Structure of a client-server model ▪ The client-server model, or client- server architecture, is a distributed application framework dividing tasks between servers and clients, which either reside in the same system or communicate through a computer network or the Internet. ▪ The client relies on sending a request to another program in order to access a service made available by a server. ▪ The server runs one or more programs that share resources with and distribute work among clients. 11  ▪ A single server hosting all the required data in a single place facilitates easy protection of data and management of user authorization and Benefits of authentication. Client-Server ▪ Resources such as network segments, servers, Computing and computers can be added to a client-server network without any significant interruptions. ▪ Data can be accessed efficiently without requiring clients and the server to be in close proximity. 12  ▪ All nodes in the client-server system are independent, requesting data only from Benefits of the server, which facilitates easy Client-Server Computing upgrades, replacements, and relocation of the nodes. ▪ Data that is transferred through client- server protocols are platform-agnostic. 13  Addresses on the Web: IP Addressing ▪ Each computer on the internet does have a unique identification number, called an IP (Internet Protocol) address. ▪ The IP addressing system in use on the Internet is in two different formats. IPv4 & IP v6. ▪ With IPv4, each part of the address is a number ranging from 0 to 255, and each part is separated from the previous part by period, ▪ For example, 106.29.242.17 ▪ While the IPv6, is in hexadecimal format, a much richer format, allowing for much bigger address space. 14  Domain Name Addressing ▪ Most web browsers do not use the IP address to locate Web sites and individual pages. ▪ They use domain name addressing. ▪ A domain name is a unique name associated with a specific IP address by a program that runs on an Internet host computer. ▪ This program, which coordinates the IP addresses and domain names for all computers attached to it, is called DNS (Domain Name System ) software. ▪ The host computer that runs this software is called a domain name server. 15  Domain Name Addressing ▪ Domain names can include any number of parts separated by periods, however most domain names currently in use have only three or four parts. ▪ Domain names follow hierarchical model that you can follow from top to bottom if you read the name from the right to the left. ▪ For example, the domain name kab.ac.ug is the computer connected to the Internet at the Kabale University, which is an academic institution located in Uganda. ▪ No other computer on the Internet has the same domain name. 16  Uniform Resource Locators  The IP address and the domain name each identify a particular computer on  What transfer protocol to use for the Internet. transporting the file  However, they do not indicate where a  The domain name of the computer Web page’s HTML document resides on which the file resides on that computer.  The pathname of the folder or  To identify a Web pages exact location, directory on the computer on Web browsers rely on Uniform which the file resides Resource Locator (URL).  The name of the file  URL is a four-part addressing scheme that tells the Web browser: 17  Structure of a Uniform Resource Locators HTTP ▪ The transfer protocol is the set of rules that the protocol pathname computers use to move files from one computer to http://www.kab.ac.ug/index.htm another on the Internet. ▪ The most common transfer protocol used on the Domain name filename Internet is the Hypertext Transfer Protocol (HTTP). ▪ Two other protocols that you can use on the Internet are the File Transfer Protocol (FTP) and the Telnet http => Hypertext Transfer Protocol Protocol 18  WEB BROWSERS 19  WEB BROUSERS  A web browser acts as an interface between the user and Web server  Software application that resides on a computer and is used to locate and display web pages.  Web users access information from web servers, through a client program called browser.  A web browser is a software application for retrieving, presenting and traversing information resources on the WWW 20  WEB BROUSERS  All major web browsers allow the user to open multiple information resources at the same time, either in different browser windows or different tabs of the same window.  A refresh and stop button for refreshing and stopping the loading of current documents.  Home button that gets your home page  Major browsers also include pop-up blockers to prevent unwanted windows from “popping up” without the user’s consent 21  HISTORY OF WEB BROUSERS  The history of web browsers dates back into the late 1980s, when a variety of technology laid the foundation for the first web browser, WWW, by Tim Berners- Lee in 1991.  Microsoft responded with its browser internet Explorer in 1995 initiating the Industry’s first browser war.  Opera first appeared in 1996, although it had only 2% browser usage share as of April 2010, it has a substantial share of the fast-growing mobile phone web browser market, being preinstalled on over 40 million phones.  In 1998, Netscape launched Mozilla 22  MORE EXAMPLES OF WEB BROUSERS ▪ Opera by Opera Software company ▪ Safari by Apple ▪ Google chrome by Google ▪ Mozilla Firefox by Mozilla corporation 23  ▪ Search engines are programs that allow users to search and retrieve information SEARCH from the vast amount of content available on the internet. TOOLS/SEARCH ENGINES ▪ They use algorithms to index and rank web pages based on relevance to a user’s query, providing a list of results for users to explore. Popular search engines include Google, Bing, and Yahoo. 24  How to find information on the Web using search tools? ▪ A number of search tools have been developed and available to you on certain Web sites that provide search services to help you find information. ▪ Examples:  Yahoo  www.yahoo.com  Excite  www.excite.com  Lycos  www.lycos.com  AltaVista  www/alta-vista.com  MSN WebSearch  www.search.msn.com 25  Research-quality - Web Searching Search Google effectively and precisely Know when to use other search engines and web directories Evaluate what you find on the web 26  POSITIVE IMPACTS OF THE INTERNET It provides effective communication using emailing and instant messaging services to any part of the world. It improves business interactions and transactions, saving on vital time. Banking and shopping online have made life less complicated. You can access the latest news from any part of the world without depending on the TV or newspaper. Education has received a huge boost as uncountable books and journals are available online from libraries across the world. This has made research easier. Students can now opt for online courses using the internet. Application for jobs has also become easier as most vacancies are advertised online with online applications becoming the norm. 27 Professionals can now exchange information and materials  NEGATIVE IMPACTS OF THE INTERNET Addiction to social networks can disrupt an individual’s life, both personally and professionally. Some miscreants use the internet to hack into people’s accounts for spurious activities including stealing data or banking information. Yet others have been known to misuse the internet for spreading hate and terrorism, two dangerously catastrophic scenarios. Others include: cyberbullying, internet pornography, electronic gambling, 28 cyber suicide, social isolation and racism on the web, virus, wastage of time.  Thank you END 29 Template by the eLearning Unit @Kab