bis100 chapter-3 prepared by: mrs. shanu joseph1 chapter 3: going online computers larry long &...

Prepared By: Mrs. Shanu Joseph 1BIS100 Chapter-3

Chapter 3:

Going Online

ComputersLarry Long & Nancy Long© 2005 Prentice-Hall, Inc.


Objectives Understand the scope of the online world, including how to go online and understanding Internet addresses Utilize Internet browsers Access various Internet applications Be aware of critical Internet issues

Going Online


The InternetInternet: worldwide collection of networks.

It’s actually comprised of millions of independent networks at academic institutions, government agencies, commercial enterprises, and other organizations.

The Internet (Net) links over a million networks with even more Internet host server computers in every country in the world.

Going Online


Going Online

ARPANET to the InternetARPANET: network for scientists that evolved into

the Internet In 1969 a small group of scientists in the United

States created a national network that would enable scientific community to share ideas over communications links.

The Department of Defense’s Advanced Research Project Agency (ARPA) sponsored the project, named ARPANET.

In 1990 it was eliminated, leaving behind a legacy of network that evolved into the Internet.


Who governs the Internet?No one group controls the InternetInternet backbone: major communications lines of the Internet and nodes to which thousands of host computers are connected.The Internet is coordinated (not governed) by volunteers from many nations serving on various advisory boards and steering committees. There is no single authoritative organization. The volunteer organizations set standards for and help coordinate the global operation of Internet. Each independent network on the Internet makes its own rules, regulations, and decisions about which resources to make publicly available. Several organizations help coordinate Internet activities:

The Internet SocietyInternet Corporation for Assigned Names and Numbers (ICANN) World Wide Web Consortium (W3C)

Going Online


Connecting to the Internet A variety of communication channels, wired and wireless, carry digital signals between computers and over the Internet. Each is rated by its channel capacity or bandwidth which refers to the amount of digital information that can be pushed through the channel. The bandwidth or channel capacity is the number of bits a channel can transmit per second (bits per second (bps) or baud).Channel Capacities vary from 56 Kbps to 9M bps

56,000 bits per second (bps)9M (millions of bits, or megabits per second)

Going Online


Connecting to the InternetChannels with high bandwidth are called broadband. Channels with a low bandwidth is called narrowband. The generic term for high-speed Internet access is broadband access.

Going Online


Connecting to the Internet Narrowband

dialup service which is a temporary connection established by using a modem over a regular telephone line

Going Online


Connecting to the InternetBroadband

cable – cable modem Digital Subscriber Line (DSL) – DSL modem satellite – satellite dish & satellite modem wireless

access points - communication hubs that enables users to link via short range radio waves wireless LAN PC card Wi-Fi – most popular wireless standard

Going Online


The Link to the InternetThe three most popular ways to connect your PC to the Internet are: Connect Via an Internet service provider (ISP)

An Internet service provider (ISP) is any company that provides individuals and organizations with access to, or presence on, the Internet. For example BATELCO.

Connect Via an Information service gatewayInformation services are large self-contained networks. Each provides an electronic gateway to the Net; i.e. you are linked to the information services network that in turn links you to the Internet. E.g. America Online or CompuServe

communications software user ID and password

Going Online


The Link to the Internet Direct via Network connection

Is preferable to a dialup link because it gives you faster interaction with the Internet. Your PC is wired directly into the Internet, usually via a LAN. A faster connection means you don’t have to wait so long to retrieve information, execute commands, or just connect to the Internet. To have a direct connection, your PC must be connected to a LAN that is linked directly to an Internet host. This is the case with most businesses and many college computer labs.

T-1 line T-3 line

Going Online


Connecting to the Internet Transmission Control Protocol/Internet Protocol (TCP/IP)

Communication protocol that permits data transmission over the Internet. Protocol: set of rules for how computers communicateCommunications over the Net are built around this two layer protocol – the TCP protocol and the IP protocolTCP sets the rules for the packaging of information into packets. Packet: the part of a message that contains the data and the address the message is being sent toEach message or file to be sent over the Internet is disassembled and placed into packets for routing over the Internet.

Going Online


Connecting to the Internet Transmission Control Protocol/Internet Protocol (TCP/IP)

The Internet protocol (IP) handles the address, such that each packet is routed to its proper destination.

How TCP/IP worksWhen you request a file from an Internet Server computer, the TCP layer divides the file into one or more packets, associates a number with each packet and then routes them one-by-one through the IP layer. Each packet has the same destination IP address. A packet may pass through a number of servers and routers before reaching its destination. At the destination, the TCP layer waits until all the packets arrive, reassembles them, and then forwards them to users as a single file.This approach to communications is known as packet switching.

Going Online


Connecting to the Internet No PC needed

televisions video game consoles cellular phones Internet appliances

Going Online


Retrieving and Viewing Information on the Internet

Client program – Internet browser: runs on user’s computer Server program – runs on server computer The client program works in conjunction with a companion server program. The client program contacts the server program, and they work together to give you access to the resources on the Internet server.

Going Online



URL (Uniform Resource Locator) The URL is the Internet equivalent of an address. The URL gives those who make information available over the Internet a standard way to designate where Internet elements (server sites, documents, or files) can be found.

http://www.prenhall.com/long/12e/main.html access protocol - Tells your client software how to access that particular file. The http tells the software to expect an (Hypertext Transport Protocol) file that is the primary access method for interacting with the Internet. Other common access methods include ftp (File Transfer Protocol) for transferring files, news for newsgroups, and gopher for accessing information via a Gopher menu tree.

Going Online



URL domain name - Is the server address. The domain name that is a unique name that identifies an Internet host site.

top-level domains: denote affiliation.com, .edu, .gov

folder - Contains the resources for a particular topic. filename - main.html- the specific filename of the file that is retrieved from the server and sent to your PC over the Net. HTML (Hyper Text Markup Language) is the language used to compose and format most of the content you see on the Net. HTML documents are text (ASCII) files.

Going Online


Internet Browsers Browsers

Software tool that makes it possible for you to tap the information resources of the electronic world and to communicate with those living in the electronic world. Browsers have several main functions:

retrieve and view Internet-based information interact with servers download and upload information

Concepts and FeaturesBrowsers are not like the other productivity tools (word processing software) they let you retrieve and view information as well as interact with server computers.

Going Online


Internet Browsers Web site pages home page – first page you see at a site hyperlinks – allow user to click on an icon and be taken to other resources on the Internet

Navigating the Internet Microsoft Internet Explorer Netscape

Going Online


Navigating the Internet Back: go to previous page Forward: go to next page Stop: ends transmission Refresh: reload Web page Favorites: have browser remember favorite sites Location bar: where user enters URL

Going Online


Browser Plug-ins Plug-in – software that gives the browser added capabilities

Shockwave Player Flash Player Real Jukebox Liquid PlayerWindows Media Player QuickTime iPix Movies Acrobat Reader

Going Online


Browser Plug-ins Streaming audio and video

media is presented continuously instead of being downloaded can play the file in real time, with nothing being saved to disk

Going Online


Internet Resources and ApplicationsFinding information on the Web

Browsing the Net: just looking around the Internet with no particular destination in mind.

Portal – site that provides a number of services E.g. Yahoo

Searching: trying to find specific information Search engine – resource that finds sites based on user input or keyword

Going Online


Searching the Net Hits

Web page retrieved for viewing Page listed in search engine results

Tips for Searching the Net Read the rules for each search engine Try multiple search engines Follow hyperlinks Choose search words carefully Be persistent

Going Online


Searching the NetAsking Someone

Frequently Asked Questions (FAQs) lists answers to questions asked often at a particular site. Your question has probably been asked and answered before.

Going Online


Internet ApplicationsWeb Servers - The World Wide Web, affectionately called the Web, is an Internet system that permits linking of multimedia documents among servers on the Internet.

user-friendly multimedia documents hyperlinks interactive frames

Going Online


Internet Applications File Transfer Protocol (FTP) servers

easily download/upload files Anonymous FTP sites - allow anyone on the Net to transfer files without prior permission.

Communicating over the Internet E-mail Username@Domainname

Domain name for the host/network

called e-mail server file attachments

Going Online


Going OnlineNewsgroups: Electronic Bulletin BoardsA newsgroup is the cyberspace version of a bulletin board that enables Internet users to exchange ideas and information. They are mostly electronic discussion groups that organized by topic.USENET is a worldwide network of servers that can be accessed over the Internet. Newsgroups are organized by topic. You need newsreader client software or similar software. The original message and any posted replies to that message is called a thread.Mailing Lists: Listserv’sIt is a cross between a newsgroup and e-mail. Mailing lists or Listserv's are like newsgroups in that they allow people to discuss issues of common interest.. Remember, each message posted is broadcast to all on the list.Newsgroup employs pull technology while Mailing lists are push technology


Going OnlineInternet Relay Chat (IRC) The IRC protocol allows users to join and participate in group chat sessions - two or more Internet users carry on a typed, real-time, online conversation.Instant messaging

Is a logical outgrowth of e-mail. It is a convenient way for you to know when your friends, family and colleagues are online so you can communicate with them in real-time.White boarding – enables participants to sketch and illustrate ideas.

Internet TelephoneThe Internet phone capability lets you call people at other computers on the Internet. To make a phone call you must have an access to the Internet, a microphone, a speaker, and Internet telephone software. People routinely use this capability to talk for hours on international calls.


Cybertalk Emoticons or smileys

;-), : -) , : -(

Netiquette Using all capital letters is considered SHOUTING Never send unsolicited e-mail (spam) Consider your audience when forwarding Internet contentNever reveal others’ personal information Be patient with people who are just getting online (newbies)

Going Online


Netiquette Don’t comment on others’ spelling, grammar, or punctuation Keep private communications private Consider e-mail attachment size before sending to someone using dialup Confirm virus warnings before forwarding Use an anti-virus program

Going Online

bis100 chapter-3 prepared by: mrs. shanu joseph1 chapter 3: going online computers larry long &...

Documents