notes on the internet

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Lesson 1 Introduction to InternetUnit I

Internet FTP HTML HTTP

Browser Hypertext URL

The Internet

The Internet is an interconnection of computers called Networks. Networks

are small interconnection of computers sharing the TCP/IP (Transmission Control

Protocol/Internet Protocol) protocols. Each runs software to provide access to

information and view information. The Internet is the transport vehicle for the

information stored in files or documents on another computer. It can e compared

to an international communications utilit! servicing computers. It is sometimes

compared to a giant international pluming s!stem. The Internet itself does not

contain information ut provides a means to access information. It is a slight

misstatement to sa! a "document was found on the Internet." It would e more

correct to sa! it was found through or using the Internet.

Computers on the Internet ma! use one or all of the following Internet services#

• Electronic mail (e-mail). It permits !ou to send and receive mail. It

provides access to discussion groups often called $istservs% after the

software the! operate under.

• Telnet or remote login. It permits !our computer to log onto another

computer and use it as if !ou were there.

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KEYWORD

S




• FTP or File Transfer Protocol. It allows !our computer to rapidl! retrieve

comple& files intact from a remote computer and view or save them on !our

computer.

• Gopher. It is a te&t'onl! method for accessing internet documents. opher

has een almost entirel! susumed in the orld ide e* ut !ou ma! still

find gopher documents linked to in we pages.

• The World Wide Web (www or "the Web"). It is the largest* fastest

growing activit! on the Internet.

What is the World Wide Web and what makes it work

You can retrieve documents; view images, animations and video; listen to

sound fles, speak and hear voice; and view programs that run on practically any

sotware in the world, provided your computer has the hardware and sotware to do

these things.

hen you log onto the Internet using !etscape or "icrosot#s Internet $%plorer

or some other &rowser, you are viewing documents on the orld ide e&. 'he

current oundation on which the www unctions is the programming language called

(yperte%t "ark)Up Language. It is ('"L and other programming em&edded within

('"L that makes possi&le (yperte%t. Hypertext is the a&ility to have we& pages

containing links, which are areas in a page or &uttons or graphics on which you can

click your mouse &utton to retrieve another document into your computer. 'his

connectivity using (yperte%t links is the eature which is uni*ue and revolutionary

a&out the e&.

(ow do (yperte%t links work+ $very document or fle or site or movie or sound

fle or anything you fnd on the e& has a uni*ue URL (uniform resource loctor!

that identifes what computer the thing is on, where it is within that computer, and

its specifc fle name. $very (yperte%t link on every we& page in the world contains

one o the ULs. hen you click on a link o any kind on a e& page, you send a

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re*uest to retrieve the uni*ue document on some computer in the world that is

uni*uely identifed &y that UL. ULs are like addresses o we& pages. - whole

cluster o internationally accepted standards such as '/0I0 and ('"L2 make


possi&le this glo&al inormation retrieval phenomenon that transcends all political

and language &oundaries.

Wht re "etscpe n# Internet Explorer$

- %ro&ser is a computer program that resides on your computer ena&ling

you to use the computer to view orld ide e& documents and access the

Internet. !etscape and Internet $%plorer are currently the leading 3graphical&rowsers3 in the world meaning they acilitate the viewing o graphics such as

images and video and more2. 'here are other &rowsers e.g., "acwe&, 4pera,

"o5illa2. "ost o6er the same eatures and can &e successully used to retrieve

documents and activate many kinds o programs.

7rowsers rely on 3plug)in3 to handle the ancier fles you fnd on the e&.

0lug)ins are su&)programs stored within a &rowser or elsewhere in your computer

especially to support special types o fles you may click on. I you click on a link,

and your computer does not currently have the plug)in needed or the fle you

clicked on, you are usually prompted with an opportunity to get the plug)in. "ost

plug)ins are ree, and easy and sae to install on your computer.

7rowsers o6er a convenient way o navigating and managing the e& and all

the ULs you may want to keep track o. !etscape and Internet $%plorer &oth o6er

the a&ility to e)mail documents, download into diskette, print documents, and keep

track o where you#ve &een and mark the sites you want to 3&ookmark.3

'ro&sers allow you to access inormation. - We% pe is made up o

o&8ects and ('"L codes called Ts. It is like a command in programming. - T

starts with a sign ) 2 and end with a sign * 2+ (yperte%t "ark)Up Language

operates using 9 kinds o tags) the Depen#ent T and the In#epen#ent T,

which is also called Stn#,lone Ts+ - Stn#,lone Ts are tags that do not

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need a partner or an end tag. $%ample is )'R*. (owever, Depen#ent T, are

tags that used to have an ending tag. -n en# t commonly represented &y : a

slash ater a sign ). $%ample is )H-* + + + ).H-*+


Steps in /retin HT0L 1rorm

'o create an ('"L program, here is the se*uence o actions to &e done.

'he ollowing demonstrates how to start ('"L programs.

Step - 2 /lick on the Strt %utton in the Ts3%r+

Step 4 2 'he pop)up menu list automatically appears.

<elect 0rogram option rom the list.

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Step 52 'he su&menu list automatically appears.

/hoose the 6ccessories rom the list and then select the "otep#

rom the

<u&)menu list.

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Step 72 'he !otepad automatically appears.

Step 82 'he !e%t part is to write the code inside the !otepad.

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16RTS O9 6" HT0L 1RO:R60

Like other programming language, ('"L is a script language that keeps

ormat when writing a code. -lthough, ('"L does not re*uire or ollow any

te%t ormat and spacing, it still re*uires important ('"L tags to make the

scripts run.

'he ollowing are the &asic parts o ('"L program that needs to &e ollowed

in writing code.

9iure - HT0L 1rorm Structure

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1.2 )HT0L* ).HT0L* Ts

'hese tags denote the &eginning o the program though some &rowser

automatically generates the =4/'Y0$ and ('"L version and other inormation

&eore >('"L?. 'he >('"L? opening tag is written at the &eginning o the

program while >('"L? end tag is placed at the end o the code. 4nce the &rowser

recogni5e the >('"L? end tag, it is a signal that the ('"L script ends.

9.2 )HE6D* 6"D ).HE6D* Ts

'he >($-=? >($-=? tags denotes the heading part o the ('"L code.

'hese tags are written within the >('"L?>('"L? tags.

@.2 )TITLE* n# ).TITLE*

'he )TITLE).TITLE* tags are part o the ('"L that is written in &etween the

>($-=? tags. 'hese tags are used to display the title o the document. 'he 'itle o

the document can &e seen in the 7rowserAs 'itle &ar when the ('"L program runs.

B.2 )'ODY* n# ).'ODY*

'he )'ODY*).'ODY* tags are part o the ('"L code that is written within

the >('"L?>('"L? tags. 'he >74=Y? tags denote the main program. 'his iswhere you can place the content o the document you want to create.

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7elow is a sample program showing the 7asic <tructure o ('"L.

HT0L 1rorm -

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Steps in S;in HT0L 1rorm

In order to retrieve the program you have typed, there is a need to save the

program &eore &rowsing the output. 'he ollowing steps demonstrate how to save

('"L programs.

Step - 2 -ter writing your ('"L program in your !otepad, click on the Cile

option in the "enu &ar.

Step 4 2 <elect the S;e 6s option rom the list when saving the fle or the frst

time.

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Step 5 2 'he S;e 6s dialog &o% automatically appears. <ave your program in

the

=esktop &y selecting the =esktop rom the drop)down list.

Step 7 2 'ype the flename with an e%tension name o +html and click on the

S6<E %utton.

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Ho& to <ie& your We% 1e

-ter you have successully saved the program, a new Internet $%plorer

or !etscape Icon will appear on your desktop. 7elow is the sample icon.

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=ou&le)click on the Icon la&eled as <-"0L$ to see your program output. I there

were changes in your program, to update, click on the Refresh %utton (Icon of

Refresh! for Internet Explorer and Relo# (Icon of Relo#! for "etscpe

";itor.


7elow is the sample output o your program.

1rorm Output -

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You can ormat the ont style and ont color o your te%t using a ormatting

tags such as )9O"T* t+ (ere are other tags that can &e used or te%t

ormatting.

-+ )9O"T* ).9O"T* t

'his tag is used to ormat the style, si5e, and color o your te%t. 'he

96/E= SI>E= and /OLOR are )9O"T* attri&utes that makes your te%t

caption set on your desired ormat.

Exmple2

)9O"T C-/$D :<'YL$ 4C C4!' <IE$D :B /4L4D7LU$*

9. )/E"TER* )./E"TER*

'his tag is used to center the te%t on your &rowser. You can place your

te%t caption inside these tags to make your te%t display in the center o

your screen.

Exmple2

)/E"TER* C4" (U"-! (I<'4Y '4 $-LY /IFILIE-'I4!)./E"TER*

@. )'R* t

'his stand)alone tag is used to make the ne%t character to go to the

ne%t line.

$%ampleG

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Crom (uman (istory to )'R* $arly /ivili5ation


7elow is the sample program using te%t ormatting tags.

HT0L 1rorm 4 Usin the )9O"T*= )center*= n# )'R* ts

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In HT0L 1rorm 4, the commands 96/E, SI>E, and /OLOR are

6TTRI'UTES o the )9O"T* t which take e6ect on all the output o the

program. 'he >center* t takes e6ect on the output :FROM HUMAN HISTORY TO

EARLY CIVILIZATIONH while the command )'R* makes way or another line on

the word :THE NEOLITHIC REVOLUTION aligned to the let.


7elow is the program output o ('"L 0rogram 9 that used attri&utes 96/E=

SI>E= and /OLOR. It also used the )'R* t.

1rorm Output 4

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'he ollowing sample program uses another te%t ormatting tags that is useul

when you want to emphasi5e your display caption.

HT0L 1rorm 5 Usin )stron*= )i*= )sup*= )%i* n# )smll* ts

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'he ollowing is the program output o ('"L 0rogram @ that used other

ormatting tags.

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1rorm Output 5


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KEY1OI"TS



• - &rowser is a computer program that resides on your computer ena&ling you

to use the computer to view www documents and access the Internet taking

advantage o te%t ormatting, hyperte%t links, images, sounds, motion, and

other eatures. !etscape and Internet.

• The Internet is an interconnection of computers called Networks. Networks

are small interconnection of computers sharing the TCP/IP (Transmission

Control Protocol/Internet Protocol) protocols. Each runs software to provide

access to information and view information.

• FTP or File Transfer Protocol allows !our computer to rapidl! retrieve

comple& files intact from a remote computer and view or save them on !our

computer.

• In#epen#ent T is also called Stn#,lone Ts which do not need an end

or partner.

• Depen#ent T is the tag which has an end tag that is represented &y a

slsh (.!+

• If there &ere chnes in your prorm to up#te clic3 on the eresh

&utton Icon o eresh2 or Internet $%plorer n# eload Icon o eload2 or

!etscape !avigator+


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H6"DS,O" 6/TI<ITY2

I+ /rete prorm tht &ill #isply the ?2

1.2 1st statement :elcome to -sian (istoryH in center with ont style D -rial7lack, si5e is and the color is Jreen,

9.2 9nd statement :0-J-! -J$ ne%t line, center, with ont style D 'imes !ewoman, si5e is B and the color is Jray

@.2 @rd statement :-'(UI-! 4"-!/$< ne%t ine, center, with ont style D-rial 7lack and the color is ed.

II+ /rete prorm tht &ill enerte the output %elo&+

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