Introduction
Computers can be connected together using data transmission media like cables, to communicate with one another. Communication in this case will be in the form of exchange of data and information. Such interconnection of computers to achieve message transfer is called networking. This is because the computers are linked to form a net.
In most cases computer networks are unique to an organization. For example the computers in your computer laboratory may be networked. Such a network is local in nature hence it is usually called a local area network (LAN).
Definition of the Internet
The term Internet can be broken down into two words, inter and net which implies that there is an interconnection of networks. Internet is therefore a large network of networks that covers the whole world and enables millions of computers from different organizations and people
To communicate globally. Because of its large size and great volume of information that passes through it, it is sometimes called the information superhighway.
Because of the flexibility of Internet technology, many organizations are creating their own private networks using the technology of the Internet. In this book we shall refer to the Internet (with capital letter I) as the information superhighway and the internet (with lower case letter (i) to refer to smaller networks.
5.3 Development of the Internet
In 1969, a research body in the USA called Advanced Research Projects Agency (ARP ) set up a computer network that connected four universities and was given the name ARPAnet. This network is viewed as the forerunner of today’s Internet. The aim was to allow sharing of data and information between computers. The main benefit was that there was fast communication between researchers through electronic mail or e-mail.
ARPA’s goal was to allow multiple users to send and receive information at the same time. The network used a special data transmission technique called packet switching which was later adopted for the Internet. A computer would send a packet that contained data, destination address information, error detection control information and packet sequencing information. By 1973 e-mail was the most common service on the Internet. It was not until 1979 that the first media companies connected to the Internet.
By 1981, many people had seen the importance of computer networking and the Internet. ARPAnet formed the backbone on which many organizations started connecting to, hence expanding it. The American military also became a big user of the Internet because they could communicate and tap into the resources available on the net. Next, the American Government decided to access the Internet for commercial purposes hence greatly increasing the traffic. By this time, for every twenty days, a new host computer was connected to the net.
By 1987, the Internet boasted of 10 000 host computers. However, its access was largely limited to the United States of America and some nations in Europe. As the importance of the Internet grew, businesses spent billions of dollars to improve it in order to offer better services to their clients. Fierce competition arose among software and hardware manufacturers as they came up with new technology to meet internetworking needs. The result was a great increase in message transmission capacity (bandwidth) and it became cheaper to work with the Internet.
By 1994, 3 million computers were connected to the Internet. Today, the Internet has grown and covered the whole world. Governments, private organizations and individuals are using the Internet in all spheres of daily life to send messages and conduct business.
Importance of Internet
The Internet is an extensive system of interlinked yet independent networks. It has evolved from a specialised communication network previously only used for military and academic purposes to a public network that is changing the way people carry out their daily activities.
The Internet is playing a very important role in all aspects of life, leading to the emergence of an elite society called the information society. The Internet’s importance can be between through its contribution to research, news and information dissemination, leisure and communication, a place to do business and many other profitable activities.
Internet connectivity requirements
For a computer to be able to connect to the Internet, there are several requirements one of them is to connect to a telecommunication service provider in order to transmit data over a wide region. This section seeks to discuss some minimum requirements for Internet connectivity to be achieved.
Telecommunication facilities
The Internet heavily relies on telecommunication facilities like the telephone lines, telephone exchange stations and satellite transmission in order to cover the whole wide world. Indeed, without these facilities, the Internet is as good as dead.
Therefore, a computer is connected to the external world through a telephone line and has to dial a remote computer on the net to establish a connection for data transfer. Dial-up connections, however, are quickly being replaced by dedicated digital data transmission telephone lines called dedicated digital leased lines. A leased line connection ensures constant and quick connection to the Internet unlike the dial-up that you need to dial every time you need to access the Internet.
Transmission of data on land takes the form of telephone exchange to telephone exchange until the data reaches the destination. However, intercontinental transfer of data is achieved by having satellite base stations transmitting g the data through a wireless uplink channel to the satellite. The satellite then sends the data signal to the base station on another continent where it is picked up and sent to telephone exchanges
For transfer to the destination computer. Figure 5.1 shows a simple logical illustration of the Internet.
Modems
A computer needs a special digital to analog and vice versa interface card called a modem that enables it to send and receive data on telephone lines. Remember that voice transmission on telephone lines is analog in nature while computers work with digital data. However, digital telephone lines make it possible for computers to transmit and receive digital data without a modem.
The word modem is short form for modulator – demodulator. During modulation, the data to be transmitted is changed from digital to analog so that it can be transmitted on the telephone lines. At the receiving end, the data is changed from analog to digital for the computer to understand it through a process called demodulation.
In most cases a modem is bought separately and plugged in one of the expansion slots on the motherboard. Some modems are external hence the computer may be connected to them through a network interface card. Most computers today come with an internal modem permanently fixed on the motherboard called an onboard modem.
Internet service providers (ISP’s)
These are companies that offer internet services to end users. For example, in Kenya, until recently, the sole gateway to the Internet for a long time was Telkom’s Jambonet. However, because Jambonet cannot meet the service needs for all users in Kenya, they lease some of their stake to Internet service providers like Africaonline@ and Swiftkenya@ who can now provide Internet services to the end users at a fee.
Internet software
The Internet interconnects millions of computers and telecommunication devices that have different configurations for hardware and software. Therefore, to achieve communication between these otherwise incompatible devices, special software called protocol is needed. A protocol is a set of rules that governs how two computers can send and receive data on the network.
For the Internet, the most common protocol is the Transmission control
Protocol (TCP) and Internet protocol (IP). As its name suggests, TCP governs how data is transferred from one place to the next, while IP determines the addressing system on the Internet. For example, each network and computer on the Internet is recognised by a special number called the IP address that enables data to be sent and received by it. These two are combined to form the TCP/IP protocol suite that is needed by any computer that needs to be connected to the Internet.
Internet services
The Internet has become very popular in today’s world because of the diverse but very important services that it offers to people. It is “seductive” i.e. once a person connects to it they find themselves falling in love with its power to provide information and services. The temptation is to continue using the Internet again and again.
The World Wide Web (www)
The World Wide Web can be viewed as a vast virtual space on the Internet where information pages called websites are installed. Most local area networks have a special computer called a server that stores information and data for others on the same network to access. In order to connect a network to the internet, the local area network needs an Internet server. This server is usually given the name world wide web (www) and has all the information that others on the Internet access. Hence, www is created by a network of Internet servers!
To enable easier access to information and data on the Internet, a standard method of preparing documents to be put on the Internet was developed. This method uses a special language such as hypertext markup language (HTML) to prepare documents called web pages that are attractive and can be accessed on the Internet. HTML can be combined with other web page production tools to achieve wonderful websites. Individuals and organizations establish sites where their web documents can be placed
2for easy access by the external world. Such sites are called websites and each has a special address called a uniform resource locator (URL) that can be used to access them. For example, one common URL address is:
http://www.yahoo.com
The first part (http) stands for hypertext transfer protocol which is a protocol that transfers hypertext. www is the name of the Internet server (web server) on which the webpage resides. yahoo.com is usually called the domain name of the local area network. It uniquely identifies a particular local area network. On the Internet, two networks may have the same web server name but never the same domain.
Electronic mail (e-mail)
This is the exchange of electronic letters, data and graphics on the Internet.
Electronic commerce (e-commerce)
Many companies are increasingly using the Internet to sell and buy goods and services. This new business strategy where goods and services are sold over the internet is called electronic commerce (e-commerce).
One advantage of e-commerce is that a company can access customers all over the world and is not limited by space and time. Hence, small companies that establish websites to auction their goods and services not only reduce operating costs but increase their sales. For example, most vehicle importers buy vehicles directly from international dealers by accessing their websites and placing orders.
However, the major challenges that face e-commerce are that people deal with each other without ever meeting physically and there is lack of proper laws to govern such business.
Electronic learning (e-Iearning)
Apart from the fact that academic materials for all levels of education are readily available on the Internet (web), the Internet has opened the door for those who would like to do distance education programs and home schooling. Learning through interaction with special programs on the computer is called electronic learning (e-Iearning).
Internet fax
The Internet provides you with complete fax facilities from your computer. You can configure fax settings, send and receive faxes, track and monitor fax activity, and access archived faxes. Using fax, you can choose to send and receive faxes with a local fax device attached to your computer, or with a remote fax device connected to fax resources located on a network.
Other Internet services
- News media on the net. All major media houses post their daily news on the Internet for their clientele to access. Hence information about an event can be sent right round the globe within a very short time.
- Health information on the net. The Internet provides latest medical news and research findings for practitioners and scholars.
- Music and entertainment on the net. It is possible to listen to music on the web and to watch video clips if your computer is a multimedia machine.
- Chatting on the net. People can sign into a chat room and exchange ideas freely through discussion. Chat rooms are a common feature and usually put together people of common interest to exchange ideas. For example, if you sign into a chartroom for politics, then you can exchange political views with otherwise unknown Internet friends who can read your typed comments as you view theirs. Try accessing www. Try. Com to see listings of chat topics that you can participate in on-line. However, you need to be careful in selecting the people to chat with on the web because some people who use the chat rooms have intentions of harming others.
Accessing the Internet
There are many applications that enable a person to access the Internet. Such applications are called web browsers. Some of them have text interface while the most popular have graphical user interface. Perhaps, the most common browsers in the world today are Netscape Navigator and Internet Explorer.
Therefore before accessing the Internet, a person must start the browser software. This book will use Internet Explorer for demonstration,
- The back button returns the browser to the immediate former webpage.
- The next button moves the browser to the next web page in case a person had clicked the back button.
- The stop button tells the browser to stop searching/loading a website.
- The refresh button tells the browser to try accessing a web site address again after failure
- The search button enables a person to search for words on the website.
- Clicking the favorites button displays all web addresses in the’ favorites” folder.
- The history button displays the website addresses that were visited in the recent past.
- The mail button enables a person to view and send mail and WebPages to links.
- The print button enables a person to print the web pages.
- The Go button tells the browser to load the current web page whose address is in the address bar.
- The address bar allows the user to type the address of a website to be accessed.
- The home button moves the user to the first page of the website.
Log in/sign in
To access a website, type the full address of the website in the address bar then press the Enter key on the keyboard. If the Internet connection is working properly, the browser will start connecting to the requested web site or URL. Notice that the status bar will be reading something like “connecting to site www.yahoo.com………………………………………………………….. “
Some web sites allow free access to all their pages by all visitors. However, others require people to be members hence a new visitor has to register (sign up) by filling some on-line forms. The registration process gives the visitor a user name and password that can be used to sign in or log on the website for each successive visit. This is very common for e-mail account providers like at www.mail.yahoo.com.
Websites that give users a chance to log in are better especially if the services offered need some degree of privacy and customizing for
Individual customers e.g. it would be a gross mistake to have everybody accessing the other’s e-mail account.
Surf/browse
Surfing or browsing is the process of accessing Internet resources like web pages and websites. This is done by either typing the URL address of a site in the address bar of the browser or by following special links that lead to web pages called hyperlinks.
Hyperlinks and search engines
A hyperlink is a text or picture on an electronic document, especially web page that causes other web pages to open when the link is clicked. A hyperlink can be identified by the fact that the mouse pointer changes to look like a palm having four folded fingers with the index finger not folded but pointing outwards.
The Internet is a big forest of web pages and websites. Searching for particular materials or resources can be a nightmare because of the massive volumes of available documents and resources. To make the work a bit easy, special websites that maintain lists of hyperlinks are available. These websites are called search engines. They have special programs called robots or spiders that traverse the web from one hyperlink to the next and when they find new material, they add them to their indexes or databases. Figure 5.4 below shows one of the most common search engines called Google found at www.google.com
The user searches for a word by typing a few key words in the search field of the engine then clicking the search button. The engine searches its database for links to the information requested and displays a list of links from which the user can now access information by clicking them to open web pages.
Example of search engines include: www.google.com, www.hotmail.com and www.yahoo.com.
Downloading/saving/printing web content
After searching and finding information on the Internet, you may want to save the information locally on your computer for future reference. The process of transferring information from a remote computer to a local storage is called downloading. To download a file, the following procedure is followed:
- Right click the hyperlink to the file.
- On the shortcut menu, click the Save target as command.
- After some searching the browser displays the save as dialog box. Specify the folder or drive where the file is to be saved then type a unique name for the file in the name box.
- Click the Save button and the download progress dialog appears on the screen. Unless otherwise selected, the download dialog will notify the user at the end of the download process.
Pen the file in its application to view it.
NB: If you download a file whose application is not currently installed on the computer, then you may not be able to view its contents. For example, if you download a file that was created in Microsoft Word then you can only open it in the same application.
To print a file, open it in the application in which it was created then send it to the printer for printing. You can also print a web page directly from the browser window by clicking File then Print.
Electronic mail (e-mail)
Electronic mail refers to the sending and receiving of electronic letters and documents on the Internet. This feature serves to popularize the Internet even among non-technical people. For many, gone are the days when paper mail (of late called snail mail) would be sent and the recipient had to wait for long before receiving it. E-mail is fast because it takes
Only a few seconds to reach the recipient regardless of where they are in the world.
E-mail software
E-mail software falls under a special group of application packages called communication SoftArt. It is specially designed and developed to help a person to read and send individual text documents on the Internet as long as both the sender and receiver have an e-mail address.
Like the normal postal address, an e-mail address directs the computers on the Internet on where to deliver the e-mail message. A typical e-mail address would look like this: chemwex@yahoo.com
- chemwex is the user name and is usually coined by the user during E-mail account registration.
- @ is the symbol for Hat” which actually separates the user name from the rest of the address.
- Yahoo. Com is the name of the host computer in the network i.e. the computer on which the e-mail account is hosted.
- The period H. ” is read as dot and is used to separate different parts of the e-mail address.
- Com identifies the type of institution offering a particular service(s) and is called the domain, meaning it is a commercial institution. Other common domains include:
Domain Type
.edu Educational institution
.gov Government institution
.org Non-profit making organization
.mil Military organization
.co Commercial institution
Sometimes another two letter extension is added after the domain name to show the country where the site is located e.g. injsmith@yahoo.co.uk, .uk stands for United Kingdom. Other countries domain name includes .ke (Kenya) .ug (Uganda, :tz (Tanzania), .jp (Japan), .au (Australia) etc.
E-mail facilities
Basically all e-mail software packages provide the user with ability to receive messages, display them, reply to the messages, compose new ones and store received messages. ‘
Mails
- Checking mail In order to check mail the user has to open the email account by providing the correct user name and password. While
In the e-mail account, click the Inbox command to view a link list of all the mails that you have received. To view a message, simply click its link and it opens on the screen for reading.
- To compose a message, click the Col11posebutton. The e-mail software opens a blank screen on which you can type the new message. Figure.5.5 shows a typical e-mail screen for composing a message.
- To send mail, type the correct e-mail address of the recipient in the to: text box. Type a subject in the subject box e.g. if it is a letter to a friend, type “Hi”. Finally click the Send, or send / receive button, and your message will be sent.
- Forwarded messages can be read and sent on to other people. Most of such messages are fun pages, poems, e-cards etc. After reading, Simply click the Forward button and then provide the addresses of the recipients. Click the Send button to send.
- An e-mail message can be saved using the normal procedure for saving e.g. Click File, Save as then provide the name of the file and click save button.
- To print e-mail, select the text to be printed then click the File – Print command. In the print dialog box select the options for the page size, orientation etc. then click the Print button.
File attachment:
E-mail software also enables a person to attach other files like pictures, music and movie clips to an e-mail for sharing with friends before sending. The recipient can then download the attached files or simply view them on the screen. A good example where people use attachments is on-line job applications where a person attaches curriculum vitae to an e-mail message. To attach a file:
- Start the e-mail software i.e. Microsoft outlook express.
- Click File then New or open a composed e-mail.
- Specify the recipients address and the subject.
- Click the Insert menu then File attachment. A dialog box appears where you chose the file you want to attach.
- Select the file then click the Attach button.
- An attachment bar is inserted in the e-mail window with a name of the file you chose.
- Click Send to send the e-mail.
NB: You can also attach a file by simply clicking the attach button.
On-line meetings
It is possible to hold on-line meetings with people by sending mail to them. For example, on-line interviews may involve a person sending electronic mail composed of interview questions to a recipient who can read and answer back immediately. This method may not be as effective as a face to face interview or discussion but it is very useful in situations where traveling may be impossible or too expensive.
Telephone messages
Because of integration between mobile telephony and the Internet technology, it is possible to send e-mail to a mobile handset and a mobile message to e-mail account. This mobile computing is made possible by a special Internet access protocol called wireless access protocol (WAP) and wireless markup language (WML).
Contact management
Most mail programs allow the user to develop an address book which holds ‘contact information like e-mail addresses of different people along with other necessary information. The e-mail software usually provides a simple way of accessing these contacts when required. To create a new contact:
- Start the e-mail software i.e. Microsoft express.
- From the tools menu, click Address book or simply click the address book button.
- From the address book window click File then: Contact.
- Click the Name tab and enter the contact details.
- Click the Add button and add the contact into the contact list.
- Close the contact window then the address book.
5.9 Accessing information on emerging issues
The Internet is a storehouse for all types of information, presented in the form of text documents, pictures, sound and even video. Many emerging
Issues in the world today may not be properly documented in terms of hardcopy textbooks and journals but the Internet has a wide range of information concerning the issues. Emerging issues in this context refer to HIV/AIDS, drug abuse, environmental issues and moral issues.
Therefore, it is already evident that before embarking on finding any information on the web, a person needs to carefully plan their search to
Avoid wasting a lot of time wading through “junk” or useless material.
Steps for searching
- Plan for your search. You must develop a search strategy. Consider the following questions before starting to search for information:
- what would be the best place to find the information required?
- What tool best suits the work at hand?
- What key words can best describe the search problem?
- There is always the best place to start the search. One of the best places is on websites of leading media houses like www.cnn.com and www.nationaudio.co.ke because you are likely to get links to the latest research discoveries in your area of interest.
- after checking out on the news houses, you can now open some search engines and type the key words in the search field. Use different search engines to look for information on all the emerging issues mentioned above because different search engines give different search results.
