1

Jordan University of Science & Technology

Faculty of Computer & Information Technology

Department of Computer Science

CIS 100

InterInternetnet

2

What is Internet?What is Internet?

Internet is a global computer network Internet is a global computer network of inter-connected networks. of inter-connected networks.

3

Internet ActivitiesInternet Activities1.1. All computers connected to the internet must All computers connected to the internet must

communicate with each other using set of rules communicate with each other using set of rules (protocols) called TCP/IP ((protocols) called TCP/IP (Transmission Control Transmission Control Protocol/ Internet ProtocolProtocol/ Internet Protocol))

2.2. Send and receive Send and receive eelectronic lectronic mmessages (essages (ee--mmailail))3.3. Transfer data files to and from computers around Transfer data files to and from computers around

the world (the world (FFile ile TTransfer ransfer PProtocol [rotocol [FTPFTP]]))4.4. View corporate or personal documents containing View corporate or personal documents containing

graphical hypertext content (graphical hypertext content (World Wide WebWorld Wide Web))5.5. Share point-of-view on specific subjects with other Share point-of-view on specific subjects with other

online groups, (online groups, (Usenet news-groups - Network Usenet news-groups - Network News Transfer ProtocolNews Transfer Protocol))

4

Internet AddressingInternet Addressing EachEach computer directly linked to the Internet computer directly linked to the Internet

mustmust obtain a unique address obtain a unique address soso that it can be that it can be located.located.

A computer’s A computer’s internet protocolinternet protocol ( (IPIP) ) addressaddress is a is a four-part seriesfour-part series of numbers separated by periods. of numbers separated by periods. For example For example 198.137.241.30198.137.241.30

BecauseBecause it is difficult to remember a long series it is difficult to remember a long series of numbers( i.e. of numbers( i.e. IPIP addressaddress ), a name addressing ), a name addressing system was developed, called domain name system was developed, called domain name system (system (DNSDNS), For example ), For example Whitehouse.govWhitehouse.gov

The The DNSDNS: is a world-wide system of databases : is a world-wide system of databases that that mapsmaps domain namesdomain names with theirwith their corresponding IP addresscorresponding IP address..

5

How To Get Internet How To Get Internet Connection?Connection?

To obtain an Internet domain name, It is To obtain an Internet domain name, It is necessary to register with (and pay) a special necessary to register with (and pay) a special Internet committee, Internet committee, Internet Service Provider Internet Service Provider (ISP)(ISP)

ISP examples: ORANGE, Batelco, TE Data, and ISP examples: ORANGE, Batelco, TE Data, and ZainZain

To get internet service:To get internet service: Subscribe with any Internet Service Provider (ISP) Subscribe with any Internet Service Provider (ISP)

6

Site TypesSite Types

The top-level specification:The top-level specification: .com.com: commercial organization.: commercial organization. .edu.edu: education.: education. .int.int: international organization.: international organization. .mil.mil: military organizations.: military organizations. .org.org: nonprofit and research : nonprofit and research

organizations.organizations. .net.net: network and service operations.: network and service operations.

7

Country CodeCountry Code

Two-letter country code:Two-letter country code:

.us: United States..us: United States.

.jo: Jordan..jo: Jordan.

.uk: United Kingdom..uk: United Kingdom.

8

Domain NameDomain Name

Second-level Second-level domain namedomain name (it is the (it is the company or organization name)company or organization name): up to 22 : up to 22 alphanumeric characters and cannot include alphanumeric characters and cannot include spaces (spaces (although underscore can be usedalthough underscore can be used).).

examples of the Domain name: examples of the Domain name: www.example.netwww.example.net www.yahoo.comwww.yahoo.com www.hotmail.comwww.hotmail.com

The alphanumeric character set consists of the numbers 0 to 9 and The alphanumeric character set consists of the numbers 0 to 9 and letters A to Z. letters A to Z.

9

Subdomain NameSubdomain Name

Subdomain NameSubdomain Name: : Put it to the left of thePut it to the left of the domain namedomain name We We maymay have additional subdomain have additional subdomain

namesnames It is It is optionaloptional part part

Subdomain NameSubdomain Name examples: examples: www.www.ciscis.just.edu.jo.just.edu.jo www.www.mailmail.yahoo.com.yahoo.com

10

Domain, LAN, and Network Domain, LAN, and Network Server Server

This entire domainThis entire domain isis part of part of LANLAN connected to connected to the internetthe internet. .

The The network servernetwork server is connected to the is connected to the Internet.Internet.

SoSo each of the computers on the network each of the computers on the network gaingain their access to the Internet their access to the Internet through through the the network servernetwork server..

LANLAN: : LLocal ocal AArea rea NNetworketwork HostnameHostname: i.e. the : i.e. the Host ComputerHost Computer

11

What is the What is the World Wide WebWorld Wide Web??

The World Wide Web is a collection of The World Wide Web is a collection of host machineshost machines:: which deliverwhich deliver documents, graphics and documents, graphics and

multi-media multi-media toto users users viavia the Internet. the Internet.

12

World Wide Web World Wide Web

Pages or files are stored on Pages or files are stored on Web ServersWeb Servers. . Users access these pages using a Users access these pages using a graphical graphical

browserbrowser like: like: Internet ExplorerInternet Explorer Netscape CommunicatorNetscape Communicator

Pages can include:Pages can include: Graphics, sound, movies and other media-rich Graphics, sound, movies and other media-rich

contentcontent References to other pages on the same site or References to other pages on the same site or

other sitesother sites

13

Hyper-LinksHyper-Links

A hyperlink is a clickable link to another A hyperlink is a clickable link to another document or resource. It is normally document or resource. It is normally shown in shown in blue underlineblue underline. .

When a user clicks on this link When a user clicks on this link The client will retrieve the document The client will retrieve the document

associated with that link byassociated with that link by requesting the document from the designated requesting the document from the designated

server upon which it resides. server upon which it resides.

14

URLsURLs

An URL (Uniform Resource Locator) is An URL (Uniform Resource Locator) is a means of specifying the a means of specifying the pathnamepathname for any resource on the Internet. for any resource on the Internet.

The URL consists of three part: The URL consists of three part: 1.1. protocol partprotocol part

2.2. host part host part

3.3. document name document name

15

URLs ExampleURLs Example

http://www.just.edu.jo/cis100/http://www.just.edu.jo/cis100/windows.htmwindows.htm

specifies the specifies the protocolprotocol asas httphttp, ,

the the host or WWW serverhost or WWW server asas just.edu.jojust.edu.jo

and the and the documentdocument asas //cis100/windows.htmcis100/windows.htm

16

Search EnginesSearch EnginesBecauseBecause there is so much information there is so much information

available on the Internet today available on the Internet today soso::it is important to be able to access it is important to be able to access

information information quickly. quickly. Several sites have specialized in Several sites have specialized in

searchingsearchingSearch EnginesSearch Engines ExamplesExamples::

www.yahoo.comwww.yahoo.comwww.google.com www.google.com www.excite.comwww.excite.comwww.metacrawler.comwww.metacrawler.com

17

Browsing the WebBrowsing the WebThe features of World Wide Web (WWW) are:

server provides WWW access information presented as pages uses html (hyper-text markup language) to

write pages pages may reference other pages, graphics etc pages may reference other pages, graphics etc

(links) (links) client provides browse services to view pages client provides browse services to view pages

and handle special page typesand handle special page types connect only long enough to get a page connect only long enough to get a page Examples of available browsers include Examples of available browsers include

Netscape Communicator and Internet Explorer.Netscape Communicator and Internet Explorer.

18

HTMLHTML

HTMLHTML: : Hyper Text Markup LanguageHyper Text Markup Language.. Used toUsed to create (design) Web pages which create (design) Web pages which

may includemay include:: Text, graphics, sound, video and/or links to Text, graphics, sound, video and/or links to

other pagesother pages

19

Web BrowserWeb Browser A A WWW browserWWW browser is an application is an application run on run on

a user’s computera user’s computer which allows him to view the pages made which allows him to view the pages made

available by a available by a WWW serverWWW server The browser interprets each HTML page The browser interprets each HTML page

and displays the information in a window. and displays the information in a window. Each Each WWW serverWWW server has a has a host namehost name, and , and

each page has a location address where it each page has a location address where it resides on the server. resides on the server.

20

Example

http://www.just.edu.jo/index.htm

The site-name is www.just.edu.jo which denotes the server address for the WWW

server at JUST The page, which is shown as JUST’s home page

is called index.htm

21

EElectronic lectronic MMail (ail (eemailmail))

Electronic mail, or email, is: Electronic mail, or email, is: a simple tool for exchanging messages a simple tool for exchanging messages

between individuals or among larger between individuals or among larger audience.audience.

22

Electronic Mail Electronic Mail

Email messages travel very quickly and Email messages travel very quickly and inexpensivelyinexpensively

The delivery of messages from one part of The delivery of messages from one part of a country to another may take minutesa country to another may take minutes

Once a message has been received, it can Once a message has been received, it can be saved, printed, edited, forwarded to be saved, printed, edited, forwarded to another user, or deletedanother user, or deleted

Email is becoming one of the most widely Email is becoming one of the most widely used services on the Internet:used services on the Internet:

23

Email CharacteristicsEmail CharacteristicsEmail is becoming one of the most Email is becoming one of the most

widely used services on the widely used services on the

Internet Internet ::1. Fast1. Fast

2. Can save messages for future 2. Can save messages for future reference.reference.

3. Free of charge.3. Free of charge.

24

How to get email account How to get email account ??

How to get just email?How to get just email? From the From the University University (Engineering Building, C3- (Engineering Building, C3-

level 1 ?)level 1 ?)

Get a free web-based email account Get a free web-based email account through yahoo or Hotmailthrough yahoo or Hotmail

25

Email AddressEmail Address

An email address has two parts:An email address has two parts:

1. Username1. Username

2. Domain Name2. Domain Name

Email Address Example: Email Address Example:

ahmad@just.edu.joahmad@just.edu.jo

26

Email Message’s PartsEmail Message’s Parts

An email message must have at least An email message must have at least two parts:two parts:

1. Header1. Header

2. Body2. Body

3. 3. Message Signature (optional)Message Signature (optional)

27

Email Message’s PartsEmail Message’s Parts

1.1. The The Message HeaderMessage Header contains contains information about the message: sender, information about the message: sender, receiver, date and subjectreceiver, date and subject

CCCC : : CCarbonarbon C Copyopy BCCBCC: : BBlind lind CCarbon arbon CCopyopy

2.2. The The Message bodyMessage body contains the actual contains the actual message being sentmessage being sent

3.3. Message Signature (optional) (see next Message Signature (optional) (see next slide)slide)

28

Message SignatureMessage Signature

Sometimes, an email message contains a Sometimes, an email message contains a third part, called third part, called the signaturethe signature

It is optional, and usually identifies or It is optional, and usually identifies or provides information about the provides information about the message’s sendermessage’s sender

29

ReviewReview CCCC : : CCarbonarbon C Copyopy BCCBCC: : BBlind lind CCarbon arbon CCopyopy ProtocolsProtocols: set of rules : set of rules TCP/IP :TCP/IP :Transmission Control Protocol/ Internet Transmission Control Protocol/ Internet

ProtocolProtocol)) FFile ile TTransfer ransfer PProtocol [rotocol [FTPFTP] ] use touse to::

Transfer data files to and from computers around the world?Transfer data files to and from computers around the world?

internet protocolinternet protocol address : address : IPIP addressaddress DNSDNS: it is a name addressing system was : it is a name addressing system was

developed, called domain name system (developed, called domain name system (DNSDNS)) URL: Uniform Resource LocatorURL: Uniform Resource Locator HTMLHTML: : Hyper Text Markup LanguageHyper Text Markup Language