Transcript Chapter 01 - Introduction to Internet

Chapter 1: Internet
Learning Outcomes:
 Describe Internet works, Internet providers,
connections, and protocols.
 Discuss e-mail, mailing lists, newsgroups,
Internet relay chat, and instant messaging.
 Describe Internet services: Telnet, FTP, and the
Web.
What is Internet?
 A “network of networks” or “the mother of all
networks”.
What is Network?
 A system of interconnected computers, telephones,
or other communications devices that can
communicate with one another and share
applications and data.
History of Internet
 Early 1960s
 Early 1970s
 1980
 Late 1980s
 By 1989
 By 1995
 1999
Development of Internet in Malaysia
Year
Event
1988
Establishment of RANGKOM network
1991
JARING network was introduced – 1st Internet
Service Provider (ISP)
1997
Telekom Malaysia Berhad – 2nd ISP
How does the Internet work?
 Similar to the telephone system.
How to connect/access to the Internet?
Through a provider or host computer.
Three widely used providers:Colleges and universities
Internet service providers
Online service providers
Connecting to Internet
Connections
 To gain access to the Internet
 Can be made either directly to the Internet or
indirectly through a provider.
 There are three types of connections: Leased and dial-up line.
 SLIP and PPP
 Terminal connection
Leased and Dial-up line
 Leased (Direct) line
 Quite expensive
 Used by organization or corporation
 Advantages:- complete access to Internet functions, and fast
response and retrieval of information.
 Dial-up (Dedicated) line
 A lower-speed connection using a modem and the public phone
system.
 Support only a single user
 Advantages:- Inexpensive and available everywhere.
Requirement to Access the Internet
 Computer
 Modem
 Account
 Communication software
 Internet software
Internet Addresses
 To send and receive e-mail on the Internet.
 To interact with other networks.
 Every network and computer user must have a
unique address.
 Uses an addressing method known as the domain
name system (DNS).
 To assign names and numbers to people and
computers.
 DNS name – made of a domain and one or more
subdomains.
 Numerical – IP Addresses. E.g.: 128.16.4.23
Example of Internet address
[email protected]
 lim.liyen – user name
 @mmu.edu.my – domain name
 @mmu – host computer
 edu – next-level domain / top-level domain
 my – highest-level domain
TCP/IP Protocol
 Before information/message is sent over the
Internet – it is broken down into small parts
called packets.
 Protocols control how messages are broken
down, sent, and reassembled.
 They govern how and when computers talk to one
another.
 The standard protocols for the Internet –
transmission control protocol/Internet protocol.
World Wide Web (the Web)
 Internet services that uses hypertext to link from document
to document and from computer to computer.
 Hypertext – a system in which documents scattered across
many Internet sites are directly linked with hyperlinks.
 Hypertext
Transfer Protocol (HTTP) – the
communication rules that allow browsers to connect with
web servers.
 Uniform Resource Locator (URL) – the web-site’s
unique address.
Continue…
 Example of a URL
http://www.nps.gov/yose/camping.htm
 http:// - Protocol
 www.nps.gov/ - Domain name (web server name)
 yose/ - Directory name, or path
 camping.htm – File (document) name and extension
 Browser – software that enables users to view web
pages and to link from one page to another.
 HyperText Markup Language (HTML) –
programming language for the documents files that are
used to display Web pages.
Continue…
 Web page – a document on theWWW.
 Web site – the location of a web domain name in a
computer somewhere on the Internet.
 Homepage – opening page ofWeb site.
 Web server – a computer that delivers requested Web
pages.
 Webmaster – person who designs, creates, monitors, and
evaluates corporate Web sites.
Continue…
 How to find Information on theWWW?
 Knowing the URL of the site.
 Browsing
 Search Engine
Browsing
E-mail
 A mode of communication via computer to send and
receive messages instantly from one network to another.
 An E-mail system consists of two programs : User agents
 Mail delivery system
 E-mail address – used to send and receive messages.
 A mail box – storage location residing in the computer
that connects us to the Internet.
 Mail server – the server that contains mailboxes.
Sending email
Continue…
 Simple Mail Transport Protocol (SMTP) – controls
the mail delivery within the Internet.
 Post Office Protocol (POP) – communication
protocol used to retrieve e-mail from a mail server.
 Advantages: Very fast
 Can be sent at the sender’s convenience
 The recipient can read the message at his/her leisure
 Easily be sent to one person, several, or to many.
Continue…
 E-mail Structure
 Consist of two very important components: Header lines
 To:
 Cc:
 BCc:
 Subject:
 Mail body
Continue…
 E-mail Software
 Emotions
 Address book
 Mailing List
 Signatures
 Message Filters
 Mail Folders
 Attachment
Mailing Lists
One type of discussion group available on the Internet.
 Use e-mail subscription and list addresses.
 Members of a mailing list communicate by sending
messages to a list address.
 List-serves (Listservs) – e-mail mailing lists of
people who regularly participate in discussion topics.
Telnet
 A program or command that allows us to connect to
remote computers on the Internet using a user name and
a password.
 Useful for perusing large databases at universities,
government agencies, or libraries.
 Advantages: We can be almost anywhere in the world and telnet to
your place of employment as if you were on site.
 We can work on computer resources that may not be
available locally.
FTP - File Transfer Protocol
 A method whereby you can connect to a remote computer
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called an FTP site and transfer files to your own
microcomputer’s hard disk.
FTP server – computer that allows user to upload and
download files using FTP.
FTP site – a collection of files that reside on a FTP server.
Host computer – remote computer – accessible via Internet
Client computer – our own computer
Download – transfer of files from the host computer – the
client computer.
Upload – vice versa
Continue…
 Basic steps in FTP: Make the FTP connection by logging in to the host
computer.
 Move to subdirectory where the desired file is stored.
 Transfer the file from the host computer to client
computer (or vice versa).
Newsgroups
 Giant electronic bulletin boards on which users conduct
written discussions about a specific subject.
 UseNet – special network of computers that support
newsgroups.
 News server – computer that stores and distributes
newsgroup messages.
 Newsreader – program included with most browsers
that allows us to access a newsgroup and read or type
messages.
Continue…
Newsgroup classifications
alt.
Alternative to the mainstream groups
comp.
About computers
misc.
Groups that don’t fit into any other categories
rec.
About recreation
sci.
About science issues
soc.
About social science issues
talk.
About debates on a variety of topics
news.
About the newsgroup news
Chat Groups
 Allow direct “live” communication.
 The most popular chat service – Internet Relay Chat
(IRC).
 IRC uses two of the basic components of a TCP/IP based
network: IRC clients
 IRC servers
 Chat room – permits users to chat with each other.
 Three type of chat rooms/channel: Public
 Private
 Secret
Instant Messaging
 Allows one or more people to communicate via direct, “live”
communication.
 Provides greater control and flexibility than chat groups.
 To get instant messaging – available free, download software
and register with the service.
Netiquette
 “Network etiquette”
 Guides to appropriate online behavior
 Netiquette has two basic rules:
 Don’t waste people’s time,
 Don’t say anything to a person online that you wouldn’t
say to his / her face.
Summary
 The Internet is a huge collection of computers connected
together by thousands of interconnected computer networks.
 Through Internet Service Providers (ISP) - local or national
companies that provide unlimited public access to the Internet
andWorldWideWeb for a flat rate.
 To send and receive e-mail on the Internet and interact with
other networks, you need an Internet address.
 WWW is a standardized set of requirements that allows users,
from any point on the Internet, to access information at any
other point.
Summary
 Email is a standardized set of requirements that allows users,
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from any point on the Internet, to access information at any other
point.
Mailing list provides a very easy method for sending messages
to more than one Internet user.
Newsgroups is an online area in which users conduct written
discussions about a particular subject.
IRC allows many people from around the world to communicate.
Instant Messaging (IM) is a real-time Internet
Communications service that notifies you when one or more
people are online
Summary
 Telnet allows you turn your local computer into a terminal of a
remote host computer.
 FTP allows you to examine, send and receive files from other
computers over the Internet.