Presentation on theme: "The Internet is a global network connecting millions of computers with ability to share resources and to communicate. The internet is a computer network."— Presentation transcript:
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1 The Internet is a global network connecting millions of computers with ability to share resources and to communicate. The internet is a computer network consisting of a worldwide network of computer networks that use the TCP/IP network protocols to facilitate data transmission and exchange.
3 Advantages of using the Internet The Internet allows greater communication between all people throughout the world and breaks down geographical and cultural boundaries. The internet provides entertainment and information for millions of people through online music and movies. The Internet allows people who are otherwise isolated from the society for whatever reason to interact with the society. The Internet provides educational, health and commercial services to people anywhere in the world. The internet is changing the work place environment by allowing people to work from home and remote locations.
4 The Internet provides people with membership to a worldwide library and resource center. The Internet has become the information superhighway for the buying public with hassle free transactions that Internet shopping can offer as a result; the Internet has become the most powerful selling tool. The Internet is a source of employment for those with skills such as researchers, web site designers and webmasters. The internet offers a wide variety of software applications that can be downloaded for use for example games software, device drivers.
5 Disadvantages of using the internet The internet is a big source of pornography and this has led to moral decay for example lesbianism and homosexuality. Because knowledge is power, the internet extends division between the privileged and the under privileged. The security of data belonging to individuals, businesses and governments may be jeopardized or at risk from unauthorized access since computer experts can easily access this information. The internet enables opportunities for fraud for example illegal money transfer. The internet promotes the spread of computer viruses through junk (useless) mails and computer games.
6 There is no controlling body that verifies the validity of information or restricts illicit materials. The Internet can isolate people from direct social interaction as well as erode the socio aspect of work. More and more people are getting engulfed in virtual world and drifting apart from their friends and family. Spamming which involves sending of unsolicited electronic mails in bulk that serve no purpose and unnecessarily clog up the entire system. (Spamming refers to sending unwanted e-mails in bulk, which provide no purpose and needlessly obstruct the entire system). Computer crimes such as hacking, piracy and information theft and all these bring more invasion of privacy of individuals.
7 Unemployment as more and more less skilled people get retrenched and their roles taken up by more efficient IT experts Increased instability in man being all the time insecure for his future and is compelled to learn new things every now and then. Isolation of the old being hard for them to cope with the many IT changes. IT related health problems like eye strain, repetitive strain injury. Computer addiction by young people like playing games and over surfing Increased installation and maintenance costs
8 Positive aspects of internet: Personal/business connectivity – through E-mail, chatting, video conferencing, websites News updates through online news groups and news rooms. Secure online data storage. Internet based education and research e.g. online training, publications Tool for entertainment and leisure through online games, music and video clips, visiting of electronic zoos, etc.
9 Promotion of business through internet based trade and commerce Promotion of medicine and health through online medication and health care. Promotion of banking and finance through online banking. Widened business investment opportunities and job opportunities through; IPS’s, internet service kiosks (café), online jobs, etc.
10 Negative aspects of internet: Very high cost implications for initial capital outlay and maintenance costs. Display of illicit/dangerous (pornographic) materials on grounds of health and materials. Promotion of crime through Hacking, Piracy, and Money laundering. Internet as a source of viruses through e-mail attachments, free games, etc. Addiction where people waste a lot of time. Loss of man-hours as employees waste company time on unproductive surfing.
11 Undesirable behaviours involving the internet Spam: Electronic junk mail or junk newsgroup postings. Pirating-making illegal copies of genuine software Watching immoral websites before you are of age Illicit/criminal/illegal material Abusive and threatening messages Hacking and cracking Impersonation
12 ISP- Internet Service Providers ISPs are organizations/companies that avail Internet services to those who need them and are willing to pay for them.
13 Examples of Internet service providers Local service providers-MTN, UTL and Airtel, K2, Orange AOL and MSN-online service providers AT&T world net Comp serve interactive Microsoft network Prodigy Internet
14 Uses of Internet service providers Provide their users with a mail box which stores their e- mails on a special server called a mail server ISPs provide an address for a specific resource on the web for example addressing schemes used to link resources on the web. ISPs operate local area networks connected to the World Wide Web ISPs connect organisations and individuals to the web ISPs also provide technical support
15 ISPs provide local telephone numbers ISPs also provide the connection media such as modems Electronic mail services Leasing server space for small businesses. Web hosting services. Provision of virtual machines e.g. storage space
16 Factors to consider when choosing an Internet service provider Speed Packages and equipment Bandwidth of the ISP Nature of customers Past experience Administrative support/budget Software used Consultancy from technical specialist in that field
17 Hard ware and software requirements for internet use Computer Modem Telephone line connection Communication software Browser software. E.g. Internet explorer or Mozilla Fire fox An account with an internet service provider (Register with an ISP (Internet service provider) Network Interface Card (NIC). Transmission medium (cables or wireless) Network operating system (NOS)
18 Uses of the Internet (Why people connect to the internet) Transfer of research papers, ideas and mails Easiest way of availing product information Advertising and providing customer support internationally Access a wealth of information, news and research information Communicate with people around the world Shop for goods and services Down load and listen to music and watch videos Access educational materials Access entertainment sources Access other computers and exchange files Provide information, photographs and audio clips. Bank and invest
19 Factors affecting communication speed over the internet Slow transmission time Malfunctioning web servers Messed up connection properties Bad uniform resource locators Bad connections Traffic on the internet at any time Band width Speed of the internet service provider’s server Computer processing speed Capacity of hardware Location of software and files Network topology
20 Ways of connecting to the Internet Modem Dial-up modems Cable modems Digital subscriber line (DSL) Integrated services digital network (ISDN) T-1 LINE (leased line)
21 a) Modem The word modem is an abbreviation of Modulation DEModulation. Modulation is to covert digital signals into analog signals. Demodulation is convert analog signals to digital signals.
22 b) Dial-up modems A dial-up is temporary connection that uses one or more analog telephone lines for communications. Advantages Dial-up modems are cheap and easy to install Dial-up modems have a wide technical base because they have been in use for many years Dial-up modems are cheap to maintain Disadvantages Dial-up modems have limited speed Dial-up modems use up the whole telephone line that is it is not possible to use a modem and a phone line at the same time.
23 c) Cable modems These offer a means of connecting the computer to the Internet through a coaxial television cable instead of a telephone line. This means they offer high speed for Internet connection and are suitable for home and business use. Advantages They are very fast They do not use up the entire phone line. Suitable for home and business use Disadvantages They are expensive to buy and install. They need extra hard ware, which is an additional cost.
24 d) Digital subscriber line (DSL) This uses standard copper phone lines to transmit data in a digital form at a very high speed. Advantages This method is good for private home and small businesses as well. It uses a standard formula It does not use up the entire phone line so it can allow Internet connection and phone calling at the same line. Disadvantages Requires extra hardware Not available with all Internet service providers
25 e) Integrated services digital network (ISDN) This is an Internet connection that uses a special telephone line running directly from the hub to the users’ house or business. Advantages This computer connection is widely supported It is faster Can support more than one computer Does not hold up the entire phone line Produce clear voice conversations Disadvantages It is expensive to set up and maintain It requires extra hardware
26 f) T-1 LINE (leased line) It is a high-speed digital connection that avails a large line and is good for small to medium sized companies. Advantages It is very fast Offers a broad technical base Disadvantages It is very expensive Requires extra hard ware and services from a telephone company
27 World Wide Web (WWW) A network of servers linked together allowing access to millions of hypertext resources. WWW consists of a worldwide collection of electronic documents. WWW is a system of internet servers that supports the hypertext markup language documents. It is important to understand that the Internet is not the same as the WWW. The WWW is to the Internet.
28 The Difference between the Internet and the World Wide Web The internet is a worldwide collection of networks linked together whereas the WWW consists of a worldwide collection of electronic documents each of which is called a webpage. The internet connects millions of computers together globally, forming a network for computers to communicate with each other whereas the WWW is an information-sharing model and is a way of accessing information over the medium of the Internet.
29 Web browsers A browser is a program used to locate and display Web pages. These are programs used to interface between the web and computer users. These are computer program software that access web pages and displays them on the computer screen. These are client programs that read files from a web server. These are programs that send requests for information that is available on the internet and display the information for the user.
30 Examples of web browsers Internet Explorer (IE) Mosaic Netscape navigator Google chrome Mozilla Firefox Opera
31 Search engines Search engines are software programs used to find web sites, web pages and files on the internet. This is a program that searches documents for specified keywords and returns a list of the documents where the keywords where found. A search engine is software that searches web pages, indices them, identifies web pages related to key words and topics that you ask for.
32 Examples of search engines Alta vista Dogpile Excite Ask Jeeves Yahoo WebCrawler Google
33 Searching the web Web server: This refers to the computer that delivers web pages that you request for. Hyperlink: This is also called a link. It is a built-in connection to another related web page or part of a web page.
34 A web page is a hypertext document accessible via the World Wide Web. A web page or webpage is a document or information resource that is suitable for the world wide web and can be accessed through a web browser and displayed on a monitor or mobile device. A web page or webpage is a document commonly written in hypertext markup language (html) that is accessible through the internet or other network using a browser. A web page is a document on the World Wide Web. Every web page is identified by a unique URL (uniform resource locator).
35 List four qualities of a good web page ‹ Should load quickly ‹ Should have feedbacks ‹ Should have links to other resources ‹ Should have date of last update ‹ Should have good navigation buttons ‹ Should have a web page title and brief summary about the page
36 Why is it not good to have a lot of graphics on a web page? ‹ It may take long to load. ‹ Client computers may support different colour depths. ‹ Graphics take a lot of space. Describe how a web page is a source of information ‹ Research making ‹ Educational material- online learning ‹ Advertisement ‹ Entertainment
38 State five advantages of web publishing ‹ Easy access to information ‹ Access to market 24 hours a day ‹ Faster communication among individuals ‹ Saves money for paper and printing ‹ Bigger audience ‹ Convenient support to customers ‹ Contents can be updated whenever changes have been made.
39 Explain why a school should have a web page ‹ Present information of interest ‹ Share knowledge and information ‹ Enhance skill building like writing, editing ‹ Provide motivation ‹ Encourage pride of ownership ‹ Enhance communication and collaboration
40 A website is a location connected to the Internet that maintains one or more web pages on the World Wide Web. A website is a collection of web pages (documents that are accessed through the Internet). A website is a collection of related web pages served from a single web domain. A webpage is a document that uses http on the website covering a particular topic/related topics. A website is a collection of related web pages or World Wide Web pages maintained by an organization or an individual.
41 Types of websites News websites: Informational websites: Business/marketing websites Wikis Online social networks Educational websites: Blog Media sharing website Web portal Content aggregator Wikis Media Uploading Sites Social Networks
42 News websites: These websites provide up to date information about what is happening in the world. Examples include new vision, CNN, BBC and Bukedde.
43 Informational websites: These websites have updated information on the on a variety of fields and facts.
44 Business/marketing websites may have a catalogue that may include all the goods that you have in your company, contact address so that in case people want the goods they may be able to know how to get to you, background information of your business and mode of payment that is how your goods can be purchased and the shipping details.
45 Wikis A wiki is a website whose users can add, modify, or delete its content via a web browser using a simplified markup language or a rich-text editor. Wikis may serve many different purposes, such as knowledge management and note taking. (An example is Wikipedia, WikiHow, and Wikia) A Wiki is a site where users collaboratively edit its content.
47 Online social networks These are web sites that focus on facilitating the building of social relations among people who, for example, share interests, activities, backgrounds, or real-life connections. Social networking sites allow users to share ideas, activities, events, and interests within their individual networks. (Examples include Face book, Twitter). These are sites where users could communicate with one another and share media, such as pictures, videos, music, blogs, etc. with other users.
48 Educational websites: These are websites that have a lot of scholarly materials these may include online library, journals, educational articles and books too. Any topic of interest can be searched through this engine.
49 Blog A blog is a discussion or informational site published on the web and consisting of discrete entries (posts) typically displayed in reverse chronological order (the most recent post appears first). Short for Web log, a blog is a Web page that serves as a publicly accessible personal journal for an individual. Typically updated daily, blogs often reflect the personality of the author. A blog is a website where someone (usually a normal person - not a professional writer) writes about a topic. Blogs can be personal (someone writing about their own life, or their personal views), based on an interest (e.g. football), or some businesses also use blogs to write about new products, etc. A blog allows someone to be a writer and publisher on the Web with very little effort or cost. A blog can be setup with just a few clicks, whereas a few years ago you"d need a lot of technical knowledge to create your own website. Many blogs have systems that allow readers to leave comments and begin discussions connected with the blog posts. Blogs allow people to publish their views and opinions very easily, without anyone else checking what they are writing.
51 Media sharing website Media sharing sites allow you to upload your photos, videos and audio to a website that can be accessed from anywhere in the world. You can then share that media with the world or just a select group of friends. A Media sharing Web site that enables users to store and share their multimedia files (photos, videos, music) with others. The media is played/viewed from any Web browser and may be selectively available via password or to the general public. A media sharing site can also be used to back up files.
52 Aggregator refers to a web site or computer software that aggregates a specific type of information from multiple online sources. A content aggregator is an individual or organization that gathers Web content (and/or sometimes applications) from different online sources for reuse or resale. There are two kinds of content aggregators: (1) those who simply gather material from various sources for their Web sites, and (2) those who gather and distribute content to suit their customer"s needs.
53 Web portal A web portal is a website that brings information together from diverse sources in a uniform way. A Web portal or public portal refers to a Web site or service that offers a broad array of resources and services, such as e-mail, forums, search engines, and online shopping malls. The first Web portals were online services, such as AOL, that provided access to the Web, but by now most of the traditional search engines have transformed themselves into Web portals to attract and keep a larger audience.
56 Social Networks A social network website is a site that allows user to connect with other users who are friends /relatives, or who share similar interests. Connected users can then share information / pictures / files with each other, send messages, chat, etc. One of the biggest social networking websites is Facebook For many people, social networking sites are the main method of communicating with friends online. In fact social networks have surpassed e-mail as the main communication link for non-business Web users. Bebo Friendster Habbo LinkedIn MySpace Orkut
58 Advantages of social networking It is usually free Very easy to keep in contact with people of similar interests Very easy to contact potential new friends The site makes it simpler to get in touch with long-lost friends You can post interesting things about yourself and your achievements online. Disadvantages of social networks You lose some privacy compared to not being on a social network You may later regret posting pictures or comments that you thought funny at the time Online bullying can be a problem if someone posts unkind or untrue things about you Some people may use a fake profile - just because they say they are 15 years old does not mean that is true. Be careful when you choose to be friends with someone you have never met in real life They can be a real distraction and time waster, some people spend many hours on social networking rather than be working or studying. For example, constantly checking their twitter feeds. Take everything you see with a pinch of salt - people do like to boast and exaggerate (just like they do in real life!)
59 Cloud computing Cloud computing is a type of computing that relies on sharing computing resources rather than having local servers or personal devices to handle applications. In cloud computing, the word cloud (also phrased as "the cloud") is used as a metaphor for "the Internet," so the phrase cloud computing means "a type of Internet-based computing," where different services -- such as servers, storage and applications -- are delivered to an organization"s computers and devices through the Internet. Cloud computing refers to the use and access of multiple server-based computational resources via a digital network. Cloud users may access the server resources using a computer, notebook, smart phone or other devices. In cloud computing, applications are provided and managed by the cloud server and data is stored remotely in the cloud configuration. Users do not download and install applications on their own devices or computers; all processing and storage is maintained by the cloud server.
61 Risks exposed to cloud computing users Exposing the user to potential violation of privacy Freely collecting public data and privately storing it on the cloud’s archives. No guarantee is given to the users for free future access. A malfunction can affect a larger number of users at once because these services are often shared on a large network. There is no defined standard between the operators and any change is extremely complex therefore there are data migration problems when changing the cloud provider.
62 Advantages of cloud computing Cloud computing is probably the most cost effective method to use, maintain and upgrade information systems. Almost unlimited storage for information in the cloud gives you unlimited storage capacity. Because all the data is stored in the cloud, backing it up and restoring the same is relatively much easier that storing the same on a physical device. Software integration is usually something that occurs automatically so you do not need to take additional efforts to customize your applications. Once you register yourself in the cloud, you can access the information from anywhere where there is an internet connection. Cloud computing is easily scalable so companies can add or subtract resources based on their needs.
63 Disadvantages of cloud computing Storing information on the cloud can render the data and information vulnerable to external hack attacks and threats. Long term dependency on the cloud host for maintenance of your information is another short coming of cloud computing. Dependency on the third party to ensure confidentiality of data and information is another limitation of cloud computing. There is less control that comes when handing over all your data and information to the cloud providers.
64 Getting information on the World Wide Web (client server computing) The internet is a network designed around client server architecture. When we are surfing the internet using a web browser, we are a client, the computers that have the information are the servers called web servers. Servers and clients Server This is a computer that responds to requests for information for example an e-mail server responds to requests to send and receive e-mail messages. It is a computer that manages resources on the network and provides a centralised storage area for resources for example programs and data. Client This is a computer that requests for information from a server. Client-server computing refers to the way in which computers exchange information by sending it as servers and receiving it as clients. Computers devoted to serving web pages are called web servers.
65 URL-uniform resource locator A URL is the address of a resource on the Internet. The Uniform Resource Locator is the address of a resource available on the Internet for example http://www.lib.latrobe.edu.au A URL is an address that specifies the location of a file on the Internet (e.g. http://library.wur.nl/). A Uniform Resource Locator is the global address of documents and other resources on the World Wide Web. http://library.wur.nl/ Resources could be: Text Graphics Sounds Movies Animations Application software
66 Parts of a uniform resource locator Once you enter the URL "http://www.webopedia.com/browser.html" into your address line, the browser breaks that Web address down into three distinct parts. The Protocol: "http" The server name: www.webopedia.com The file name, which follows the server name: "browser.html" IP address-Internet protocol address. An IP address is a number that uniquely identifies each computer or device connected to the computer network or data link. For example, the domain name www.example.commight translate to 220.127.116.11. Examples of uniform resource locators http://www.cnn.com http://www.yahoo.com http://www.microsoft.com ftp://eds.ipi.arizona.com
67 Domain name The Domain name is the text version of an internet protocol address. For example, the domain name www.example.commight translate to 18.104.22.168. Domain name system (DNS) The Domain name system is a system that permits use of alphabetic characters instead of numbers for easy remembrance of the Internet protocol address. The Domain name system is a system that translates a uniform resource locator address that you type into a series of numbers. The computer uses the numbers to find websites you want to reach.
68 INTERNET SERVICES Retrieval services a) FTP-File Transfer Protocol b) Gopher Multimedia services c) WWW(WorldWideWeb/W3/Web) Search services d)WAIS-Wide Area Information Server e) Veronica- Very Easy Rodent Oriented Net-wide Index to Computerized Archives f) Archie Communication services g) E-Mail (electronic mail) h) Telnet i) Usenet (users’ net)/news groups j) IRC- Internet Relay Chats (chat rooms) k) Instant messaging L) Video conferencing m) Internet telephony (voice over internet protocol) n) Voice mail o) Mailing lists p) Message boards
69 a) FTP-File Transfer Protocol File Transfer Protocol makes it possible to send data contained in files between computers. This allows users to upload and download files with other computers. FTP server is a computer that allows users to upload and download files using FTP. FTP site is a collection of files that reside on an FTP server. Downloading refers to retrieving of files from another computer and storing the files in your computer on a network. Uploading refers to sending files from your computer to another computer on a network.
70 b) Gopher A hierarchical system for finding and retrieving information from the Internet or and intranet Is a menu-based system for exploring the Internet. Users locate resources by selecting resources from menus. A system allowing users to search for files via menus or directory structures. Is a menu-driven information system that transparently connects users to other Internet sites.
71 c) WWW(WorldWideWeb/W3/Web) A network of servers linked together allowing access to millions of hypertext resources. This consists of a worldwide collection of electronic documents. This is a system of internet servers that support the hypertext markup language documents. It is the most popular service on the internet because of the following reasons: It is simple to navigate It contains millions of documents that contain several media like graphics, sound, video and pictures. It presents a wealth of vibrant and interesting information on a variety of useful, entertaining and useless topics in any attractive way. The Difference between the Internet and the World Wide Web The internet connects millions of computers together globally, forming a network for computers to communicate with each other whereas the WWW is an information-sharing model and is a way of accessing information over the medium of the Internet.
72 d)WAIS-Wide Area Information Server This is a program for finding documents on the Internet. This is an internet search service that locates documents containing a keyword or phrase. This is a set of full- text databases containing information on hundreds of topics.
73 e) Veronica- Very Easy Rodent Oriented Net- wide Index to Computerized Archives This is an Internet tool that allows you to search by keyword through gopher titles and directories. This is a search utility that helps find information on gopher servers. Veronica allows users to enter keywords to locate the gopher site holding the desired information.
74 f) Archie A tool used for searching FTP sites for various program files. Archie is a Net- based service that allows you to locate files that can be downloaded via FTP. This is a program that enables you to search for files anywhere on the Internet by filename.
75 g) E-Mail (electronic mail) This is a service that allows a computer user to exchange messages with other computer users (or groups of users) via a network. This is a service for the transmission of messages over networks. This service enables the transfer of electronic messages from one geographical location to another using computers and related computer devices. Sending and receiving electronic mails Electronic mails involve transmission of electronic messages and files via a computer network or data link.
76 Electronic mail systems use some standardized application packages like: Lotus domino Lotus CC: mail server Eudora pro Quick mail office Microsoft outlook Pegasus Turnpike
77 Creating a new electronic mail message The main components of an electronic mail message are: The address Actual electronic mail messages are needed for people outside your organization or school network. The mail must be addressed to the person who is to receive it.
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An accurate address is a necessity for each person who is to receive the message. An example of an electronic mail address is biilbrown