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B.

Sc (Computers) III Year
Web Technologies
Unit- I

1. Explain E-mail.
A. E-Mail is one of the fastest communication information serv ice that we use in our
daily life which give facilities like sending mails, getting mails, chatting, conference,
group mailing etc. E-mail still makes up a majority of Internet Traffic because
everyone with Internet access has an e-mail account. E-mail clients are programs
that are used to manage, read and compose e- mail.

2. What a re the advanta ges and disadvanta ges of E-mail?
A. Adva ntages:
1. Convenience: A message can be informal or formal. E- mail makes publishing
and discussing very fast.
2. Speed: E-mail is fast based on the speed of the underly ing communication
network.
3. Inexpensive: Once the user is on-line, the cost of sending a message is small.
4. Printable: A hard copy is easy to obtain.
5. Reliable: Many mail systems will notify the sender if an e-mail message was
undeliverable.
6. Generality: E- mail is not limited to text; it allows transferring of graphics,
programs and even audio and video files.

Disadvantages:
1. Misdirection: It is far more likely that the user will accidentally sends e- mail to
an unintended recipient than it is for someone actually to intercept the mail.
2. Forgery: E- mail does not preclude a forgery that is someone impersonating the
sender, since the sender usually not authenticated in any way.
3. Overload: E- mail can also be too convenient and result in a flood of mail.
4. Junk: The process of sending junk e-mail to lots of sites simultaneously is
know n as spamming.
5. No Response: A mild f rustration sometimes associated with using e-mail is
dealing with recipients who do not read and respond to their e- mail on a
regular basis.

Despite of the disadvantages which are for the most part the same as those
associated with any communication mechanism, many people prefer using e- mail
to either using the telephone or writing a letter. E-mail is less formal than a letter
and not intrusive as a phone call. On the whole, the advantages of e- mail are
great and the disadvantages although real are acceptable when compared w ith
alternatives.

3. What a re userids a nd passwords?
A. Userid: It is the account name allotted to the person who is using the E-mail
service. Userid is the concatenation of the word “user” and the abbrev iation “id”
standing for identification. The userid identifies the computer.
The uppercase or lowercase is normally not signif icant in e-mail names. That is,
ABC and abc are treated as same. However, one is easier to read and may be shown
a bit more respect for the account owner. If the name is Steve Village, do not pick a
user name of Steve, since there are several million Steve in the world and such a
userid by itself would not uniquely identify the user.
Passwords: It is the secret code that authenticates the user to the computer.
This is done simply to check that the user is the only one who knows the password to
the account.
A good password should have the follow ing characteristics:
1. Be at least five characters long.
2. Contain a nonalphabetical sy mbol such as _.
3. Contain a number.
4. Possess uppercase and lowercase letters.
Uppercase or lowercase is signif icant in passwords.

4. Write a short note on Message Compone nts.
A. A sample e- mail message in most e- mail clients contains the follow ing
components:
1. Date
2. Sender
3. Size (Bytes)
4. Subject Line

Sometimes additional sy mbols are used to flag whether or not the user has
already viewed the message. The first five lines of the message are referred to as
the e-mail header.
1. The From field indicates who sent the message and when.
2. The Date field repeats the date.
3. The To field specifies to whom the message has sent.
4. The Subject f ield prov ides a short description about the message.
5. The CC field tells us that the message was “Carbon Copied” to another user.
Long ago when a duplicate message needed to be sent, carbon paper was
used to generate the extra copy, hence the term carbon copy for a duplicate
message.
6. One field that does not appear that is worth mentioning is BCC, which stands
for “Blind Carbon Copy”. BCC is used when the user do not want one or more
of the recipients to know that someone else was copied on the message.

5. Write a short note on Message Composition.
A. The manner in which the user composes an e- mail message may vary from one
mail program to another. However, the basic elements remain the same, even if the
user is composing the e-mail outside the mailer using a simple text editor.

Structure: When the user has selected the compose button or command, the
mailer’s first field is generally To field. Here the user should enter the e-mail address
of the person to whom he/she is sending the message. Then the user w ill be
prompted to enter a short description of the message called Subject. After entering
the subject, the user can specify a file to be attached to this message in the
Attachment f ield. Most mailers use text editor for message composition. The text
editor acts as a word processor. It allows the user to type and modify the message.
Also, most mailers prov ide on-line documentation about how to use this editor.

6. Define the following te rms.
(a ). Mailer (b). Mail Server (c). Ma ilbox
A. Ma ile r: A mailer is also called as a mail program, mail application or mail client.
A mailer is the software that allows the user to manage, read and compose e-mail.
Mail Se rver: The mail server is a computer whose f unctions are to receive, store
and deliver e- mail. If new e-mail has arrived, the server keeps track of it. The mailer
may be on the same computer that acts as a mail server.
Mailbox: An electronic mailbox is a disk file specifically formatted to hold e- mail
messages and information about them. The mailbox uniquely identified by the user’s
account name. On some systems, even if we remove the mailbox, it is automatically
generated for the user when new e-mail arrives.

7. Explain a bout Ma iler features.
A. A typical mailer opened in a w indow w ill contain a series of buttons or menu
items with names such as Compose, Copy, Delete, Edit, Forward, Move, Next, Reply,
View and so on.

Compose: The compose button prov ides the follow ing features
· New: Compose a message from scratch
· Reply: Replay a current message
· Forward: Pass the message on
· Vacation: The user is going away and wants automatic response to be
generated and have e- mail saved.
File: A File button has the following functionality
· Save: Save the current message into file on disk.
· Insert: Include a file in the body of the message being composed.
· Exit: Leave the mailer
· Open: Open a file from disk
· Attach: Append a file to a message.
Re ply: A Reply button usually consists of the following items
· To sender
· To all
· Forward
· Include
· Include bracketed

Brac keted Text and Include:
When reply ing to a message, keep in mind that a period of time may have
elapsed since the user received the message. Thus, a reply of Yes to a message may
have no meaning to the recipient. They may not recall whether the user is answering
the question properly or not. It is good idea to include the context to the original
question along w ith the reply.
(Original text from sender)
> (original text from sender) … Reply

Forwarding: At any given point of time. People have many e- mail addresses.
Instead of reading mails from different accounts, it is often more convenient to have
all e- mail directed to only one account. This is usually possible by forwarding all e-
mails from other account to any one account. On some systems, there is a special
hidden f ile called something like . forward, w here the user can specify the e-mail
address to which the user would like the mail from that an account to be forwarded.

8. Disc uss E-mail Inner Working.
A. E- mail works in three phases.
1. In the first phase we perform compose, address and the mail.
2. In the second phase we perform sending the mail to the destination mail box.
3. In the three phases, the recipient check for mail, retrieves the letter from the
mail box opens the envelope or gets a message for the letter sent.

Store and Forward Features:
A mail server needs to be running nearly all the time, waiting for e- mail
messages and routing them appropriately. If a mail server crashes or it is extended
period, e- mail can be lost. Thus, the mail server must be a 7 by 24 machine that is a
machine running 7 days a week, 24 hours a day.
When e- mail arrives, it is saved for the address in their inbox until they pick it
up by downloading the message. The save and pick-up processes comprise the
store-and-forward function.
There is a space limitation on the size of the mailbox. Generally once this limit
is reached, new incoming message are refused until the user frees up space by
deleting some messages.
The users obtain their e- mail by relying on Post Office Protocol (POP) to
retrieve their e- mail from a remote location. A protocol is a set of rules that
computers use for communicating with one another. Once the message arrives, the
mail server stores it one disk in an area designated. The disk storage area on a mail
server is often called mail spool which is the store part of “store and forward”.

Central Ma il Spool a nd IMAP:
One of the popular method by w hich users obtain their e- mail is through
“Central Mail Spool System”. This is particularly useful if someone is going to be
accessing e-mail from multiple computers. For example, if 2 persons want to access
the same inbox simultaneously. Lots of complications can arise in this aspect which
can handle relevant issues designed by protocol called Interactive Mail Access
Protocol (IMAP). One advantage of IMAP over some other protocols is that it encrypts
password. IMAP encodes the password so someone sniffing the network cannot
directly obtain the password. This prov ides higher security than some systems that
transmit the password as plaintext which means that the password is not encoded.

Bounce Features:
When the user sends an e- mail message, the mailer software sends a copy of
it over the Internet. The message has to be split up into small pieces called packets
containing appropriate header information and sequence numbers. The sequence
numbers are needed so the message can be reassembled in the correct order. The
mailer uses the destination e- mail address to identify the computer to which the
message should be routed. The receiving end must notify the server that all went
accordingly to plan and that the e-mail was delivered properly. This is necessary
because of mail sometimes bounces that is the e-mail is undeliverable. The major
reasons for a bounce are:
1. Bad user account name: The e- mail bounces after it gets to the target
systems and that system discovers the address does not exist.
2. Bad domain name: This causes an immediate bounce.
3. Domain name server is down for a number of days: If a mail server is not
working, the mail system w ill keep trying to send the message for a period of
time. Eventually, the mail system time out on retries and the e- mail w ill
bounce back.
4. Some other malf unction: If the message being mailed is too big, a warning
may be sent to notify this.
9. Explain a bout E-mail Manageme nt.
A. E-mail is a complex communication mechanism with many uses. To maintain
all features one can develop their own e- mail style for the better management of the
e-mails. For managing e-mail properly one should know or think about the follow ing
things.
· Does e- mail help you at work?
· Is e-mail a waste of your time?
· Are you flooded with e-mail from mailing lists?
· Are you constantly reading forwards jokes?
· How can e-mail make your life more enjoyable?
· How can e-mail make you more productive instead of less effective?
· Do you receive a lot of useless gossip?

When the user decides to view the e-mail, the mailer provides some sort of index
messages with the subject like displayed. Usually the messages are numbered in
sequence. The mailer typically displays the first or current message.

Action Options: We have a number of options for dealing with the message. Some
of them are:
1. You might decide based on the subject line and the address of the sender that
you want to decide the message without reading it. This is one way to deal
with junk e- mail.
2. You many decide that you do not have time to read the message right now
and that you w ill get back to it later. In this case, you could simply skip over
it or save it to a file.
3. You may decide to read the current message now. After reading the message,
you have the option of deleting the message, reply ing to it, forwarding the
message to someone else, saving the message in a file or saving the message
in the mailbox.

Vacation Program: A vacation program is one that automatically replies to your e-
mail. Usually the program sends a brief reply back to each message you receive. For
business purposes, it is customary to include the name and telephone number/e- mail
address to contact in your absence.
Consider the following points before routinely setting up such a program.
1. Do most of your friends know you are going away?
2. Do most of your business associates realize you are on vacation?
3. Are you subscribed to any mailing lists where 1000 or so innocent users could
be bombarded by your vacation program?
4. Do you want people to know you are away, especially stranger?
5. Does your vacation message tell recipients who to contact in your absence?

E-mail and Business: When working in a business environment that uses e-mail,
you should be aware that it is currently legal for an employer to read all company e-
mail. Very few companies actually do read employees e-mail, but you should be
aware that they can. A company could maintain backups of all e- mail for a long
period of time. If necessary they could go back and rev iew the e-mail message of an
employee.
Business sometimes uses e- mail f ilters. The filters can work in both directions
to limit either incoming or outgoing e- mails. The filtering mechanism examines each
message’s e- mail address before deciding whether or not to send the mail on.
Business use e-mail filters to restrict with their employees can communicate.
10. Explain the bare bones of a browser with neat diagram.
(or)
Explain about Browser Window Te rminology.
A. A Web browser is one of many software applications that function as the
interface between a user and the Internet. The browser not only sends messages to
Web servers to retrieve the page requests, but also parses and renders the HTML
code once it arrives. That is, the browser interprets the code and displays the results
on the screen. Many browsers have built-in mail clients and/or newsreaders.
Additionally, auxiliary programs such as helper applications and plug-ins can be
configured into the browser.
Popular browsers include Netscape Navigator, Microsoft’s Internet Explorer,
Mosaic, and Lynx. The first few are graphical- based Web browsers, whereas Lynx is
a text-only browser.

Browser Window Te rminology:
The different components of the window are:
1. Title ba r—The location where the document’s title is displayed.
2. Menu ba r—The place showing the headings of the main pull-down
command menus.
3. Toolba r—The area prov iding access to a number of single- mouse click
commands.
4. Location—The area where the Uniform Resource Locator (URL)
of the document is displayed. The item in the location field usually begins w ith
http://, file:///, https:// and ftp://.
5. Hot buttons—Single-click buttons that provide a number of convenient features.
6. Netscape icon—An image that shows movement to indicate when a document is
being downloaded f rom the Internet.
7. Scroll ba r—Arrows that allow the user to display a different part of
a “large” document.
8. Document area—The part of the window that is used for displaying
the currently loaded document.
9. Status ba r—A field used to convey helpful (and current) information to the user,
such as a URL or a programmer-specified message.
10. In-line ima ge—An image appearing w ithin a document.
11. Hyperlink—A highlighted (usually underlined) part of a document
that, when selected, causes the browser to retrieve and display a
(new) document.
Menu Ba r:
The following are the items in the menu bar
1. The File menu item w ill allows launching a new browser, utilizing the
Netscape mailer, open a new URL, open a local file, save a file, print a screen,
or exit the browser.
2. The Edit button provides basic text editing capabilities.
3. The Vie w menu item is especially useful because it allows view ing the HTML
source code of the document being displayed. Other functions allow you to
reload a page, load images, ref resh a page, obtain document information,
view frame source code, and view frame information.
4. The Go menu item displays a list of Web pages that you have v isited and
allows you to select any one to return to. It also provides Bac k, Forward,
Home, and Stop loading options.
5. The Communicator menu contains the items Collabra Discussions
(Netscape’s collaborative computing software), Pa ge Composer (Netscape’s
HTML editor), Message Center, Bookmarks, and History, among others.
6. The Bookma rks menu item lets you add a bookmark or directly select a
(prev iously saved) bookmark. A bookmar k is simply a saved Web location
(i.e., URL). URLs are often cumbersome to type.
7. The Help menu item prov ides Netscape help and information.
Toolba r:
The toolbar is located under the title bar and contains buttons for Back, Forwa rd;
Re load, Home, Sea rch, Guide, Print, Security, and Stop.

1. Back: The Bac k button allows you to access the most recently visited page
without typing its URL. The page is usually loaded quickly, since it is available
from cache.
2. Forward: The Forwa rd button allows you to page forward in much the same
way that the Back button operates.
3. Reloa d: The most current version of a Web page can be loaded by clicking on
the Reloa d button.
4. Home: The user can specify what Web page to load when the browser is first
activated. This page is often called the homepage. The Home button will load
the homepage that has been designated.
5. Search: Clicking on the Sea rch button brings up one of the many useful search
tools that Netscape “knows” about. Once the search tool is loaded, you can use
it to search the Internet.
6. Guide : The Guide button leads you to a mini information center (provided by
Netscape) from which you can locate all kinds of useful items. The information
displayed is updated frequently.
7. Print: You can obtain a hardcopy of the currently displayed Web page by
clicking the Print button.
8. Security : The Security button allows you to examine and specify security
options.
9. Stop: The Stop button is used to stop the transfer of a Web page. This button
also allows you to stop endlessly looping animated GIFs.

Hot Buttons:
Beneath the location area are the hot buttons (also called directory buttons) that
Netscape provides. Other browsers provide their own versions of these buttons.
These buttons include

• Internet: This button has the same effect as the Guide button of the tool bar.
• Lookup: This button contains two options: People and Yellow Pages.
• People: Various search programs that are available to locate an indiv idual.
• Yellow Pa ges: Various search programs that are available to locate a business.
• Ne w & Cool: This button contains two options: What’s Ne w and What’s Cool.
• What’s Ne w: A list of new, interesting Web pages.
• What’s Cool: A selected list of “cool” Web pages.
• Netcaster: This button takes you to information about Netscape’s Netcaster
product, which allows you to open a “channel” to receive a continuous f low of
information to your computer.

11. Discuss in deta il about Coast-to-Coast surfing.
A. The Web prov ides a means of accessing an enormous collection of
information, including text, graphics, audio, v ideo, movies, and so on. One of the
most exciting aspects of the Web is that information can be accessed. In a
nonlinear and experimental fashion. Unlike reading a book by flipping to the next
page in sequential order, you can “jump” from topic to topic via hyperlinks. This
nonlinear approach to information gathering, or browsing, is sometimes referred to
as “surfing the Web.”
Web Terminology:
• Page or Web page: A file that can be read over the World Wide Web.
• Pages or Web pages: The global collection of documents associated with and
accessible via the World Wide Web.
• Hyperlink: A string of clickable text or a clickable graphic that points to another
Web page or document. When the hyperlink is selected, another Web page is
requested, retrieved, and rendered by the browser.
• Hypertext: Web pages that have hy perlinks to other pages. More generally, any
text having nonlinear links to other text.
• Browser: A software tool used to v iew Web pages, read email, and read
newsgroups, among other things. Browsers are also called Web clients.
• Multime dia : Information in the form of graphics, audio, v ideo, or mov ies. A
multimedia document contains a media element other than just plaintext.
• Hypermedia : Media with links and nav igational tools.
• Uniform Resource Locator: A string of characters that specify the address of a
Web page.
• Surfe r: A person who spends time exploring the World Wide Web.
• Web presentation: A collection of associated and hyperlinked Web pages.
Usually, there is an underlying theme to the pages. For example, a Web presentation
for a company may describe facts about the company, its employees, its products,
and the method for ordering the products on-line.
• Webmaster A person w ho maintains, creates, and manages a Web presentation,
often for a business, organization, or university.
. We b ma nager: Sy nony m for Webmaster.
• Web site : An entity on the Internet that publishes Web pages.
• Web server: A computer that satisfies user requests for Web pages.
• Mirror site: A site that contains a duplicate copy of a Web presentation from
another site.

Uniform Resource Locator (URL)
The address of the Web page is a URL (pronounced “you-are-ell”). Typing a URL in
the location area and hitting the return key w ill cause the browser to attempt to
retrieve that page. If the browser is successful in f inding the page, the browser will
display it.

We can view the format of a URL as follows:
how://where/what

http://pubpages.uminn.edu/index.ht ml

1. http—Defines the protocol or scheme by which to access the page. In this
case, the protocol is Hyper Text Transfer Protocol. This protocol is the set of
rules by which an HTML document is transferred over the Web.
2. pubpages.uminn.edu—Identifies the domain name of the computer w here
the page resides. The computer is a Web server capable of satisfying page
requests.
3. index.html—Provides the local name (usually a file name) uniquely
identify ing the specific page. If no name is specified, the Web server w here
the page is located may supply a default file. On many systems, the default
file is named index.ht ml or index.ht m.
12. What is URL? Explain.
A. Uniform Resource Locator (URL) is a fancy name for web address. It contains
information about where a file is and what a browser should do w ith it. Each file on
the Internet has a unique URL.
E.g. http://www.osmania.ac.in/index.ht ml

Protocol Server Name File Name

The first part of URL is called as protocol or scheme. It tells the browser how
to deal with the file that it is about to open. One of the most common protocols is
http or Hypertext Transfer Protocol. It is used to access the web pages.
The second part of URL is the name of the server where the file is located
followed by the path that leads to the file and the file name itself. Sometimes URL
ends in a trailing forward slash w ith no file name given.
The common protocol is http. The other protocols are ftp (File Transfer
Protocol) for dow nloading f iles f rom internet, mailto for sending electronic mail and
file for accessing files on a local hard disk. A protocol is generally followed by a colon
and two forward slashes. The file protocol uses three slashes where as mailto uses a
colon without slash.
URLs are of two types:
1. Absolute URL: An absolute URL shows the entire path to the file including
the scheme, the server name and the file name.
E.g. http://www.yahoo.com/index.ht ml
2. Re lative URL: A relative URL describes the location of the desired file w ith
reference to the location of the file that contains the URL itself. The relative
URL is in the same directory as the current file is simply the file name and
extension.
E.g. index.ht ml

13. Ex pla in about how to set up a web page.
A. The HTML document contains HEAD and BODY tags. The basic tags of web
page are:

1. Head Tag: The Head tag, <HEAD> has no attributes. However, several tags can
be included inside it. The most important of these is the title tag.

a. Title Tag: A title tag, <TITLE>, is contained w ithin the head of the document to
prov ide a title for the document. Its corresponding ending tag is </TITLE>. Do not
include any HTML formatting within the title tag.

b. Basefont Tag: The basefont tag, <BASEF ONT >, defines the font size to be used in
the HTML document and may be included in the head of the document. It is also
possible to use the basefont tag in other locations of an HTML document. Most
browsers permit a range of font sizes. Seven different sizes are commonly available,
with the sizes ranging from 1, which is the smallest, to 7, which is the largest?

<HEAD>
<BASEFONT SIZE = "4">
</HEAD>
To increase the font one larger than the default we use the following code:
<BASEFONT SIZE = "+1">
In typing this tag, it is common practice to omit the double quotes. The ending tag
</BASEFONT > returns the font size to its default value.

c. Base Tag:
The base tag, <BASE>, is useful for setting some global parameters of an HTML
document and may be included in the head of the document. A global parameter is
an attribute that has an effect on the entire document.
<HEAD>
<T ITLE>Water Sports to Die For</TITLE>
<BASE HREF =
"http://www.yahoo.com/index.ht ml">
</HEAD>

d. Meta Tag:
Mot widely used tag inside the head tag is the Meta tag, <META>. This tag is used to
include additional information about a document and can be used to pass additional
information to a browser. There is no ending tag for <META> and a document can
have multiple <META> tags. The attributes of the Meta tag are NAME, CONTENT,
and HTTP-EQUIV. we should include a modest list of keywords, say three to five, as
the value of the CONTENT attribute. If someone is searching for a particular topic,
the page may be returned if one or more of your keywords match their search
request.
<HEAD>
<META NAME = "keywords"
CONTENT = "woodw orking, cabinet making,
handmade furniture">
</HEAD>

HTML and Colors
There are two ways of defining colors in HTML documents.

1. One involves straightforward color names, such as blue, cranberry, green, orange,
red, and yellow. Many browsers have a list of predefined color names.
A little computer numbering terminology is necessary first. A bit is either 0 or
the term bit stands for binary digit. Bits are useful for counting in base two.

Decima l Bina ry
0 0
1 1
2 10
4 100
5 101
29 11101
255 11111111

For example, 11101 in binary represent 29 in decimal, as follows:
(1 × 24 ) + (1 × 23 ) + (1 × 22 ) + (0 × 21 ) + (1 × 20 )
Equals 16 + 8 + 4 + 0 + 1 = 29

2. Colors in HTML documents are represented as hexadecimal numbers, which are
numbers in base sixteen. Hexadecimal can also be considered shorthand for
representing four bits, since only four bits are needed to represent the numbers 0
through 15. Since there are only 10 base ten digits (0–9), we need six additional
sy mbols in the hexadecimal number system: A, B, C, D, E, and F.

For example, 752 in hexadecimal represents the number 1874 in decimal, as follows:
(7 × 162 ) + (5 × 161 ) + (2 × 160 ) = 1792 + 80 + 2 = 1874

HTML documents are represented by three two digit hexadecimal numbers.
Each of the two digits signifies the amount of one of three primary colors. In other
words, a color is formed by mixing different amounts of red, green, and blue. The
first two digits represent the red component, the next two the green portion, and the
last two the amount of blue. This method of representing colors is called the RGB
color model.
We can view this as follows:

As an example, 000000 means 00 or no red, 00 of green, and 00 of blue. This
total absence of color is the color black. So, 000000 represents black.

2. Body Tag:
The body is the second and main part of every HTML document. The text and
HTML code that goes between the body beginning and ending tags is rendered and
displayed in the document area of the browser’s w indow. The body tag, <BODY >,
has a number of useful attributes. The most interesting attributes deal with the
document’s text color and background color, and the properties of hyperlinks.
a. Text Color: The TEXT attribute is used to change the default text color for an
entire document. Suppose you have a document and would like to use a red colored
text. The following HTML code shows how:
<BODY TEXT = "#FF0000">
b. Background Color and Image: Two attributes to the body tag that allows the user
to add values to a Web page background are BGCOLOR and BACKGROUND.

The BGCOLOR attribute is used to set the background of an HTML document to a
single color. For example, the following HTML code sets the document background
area to blue:
<BODY BGCOLOR = "#0000FF ">
We can also use color names:
<BODY BGCOLOR = "blue">

If we have an image called marble.jpg, the follow ing HTML code would include it as a
tiled background for you:
<BODY BACKGROUND = "marble.jpg">

The following HTML code first loads in a color and then a background pattern:
<BODY BGCOLOR = "#0000FF " BACKGROUND = "marble.jpg">

c. Hyperlink Colors: Three attributes are used for changing the color of a hyperlink,
where
the color depends on the current state of the hyperlink. The three possible states
are: unv isited, visited, and currently thinking of visiting. These are defined as
follows:
LINK: Unv isited hyperlinks. The color value assigned to LINK sets the color for all
unvisited hyperlinks in the HTML document.
VLINK: Visited hyperlinks. The color value assigned to VLINK sets the color for all
visited hyperlinks, that is, hyperlinks the user has already explored
ALINK: A hyperlink the user is thinking of v isiting. The A stands for active hyperlink.
The color value assigned to ALINK sets the color of a hyperlink that the user has
moused over and depressed the mouse button on.

The following code specifies unvisited links as red, v isited links as gray,
and the active link as yellow:
<BODY BGCOLOR = "#FFFFFF"
LINK = "#FF0000"
VLINK = "#808080"
ALINK = "#FFFF00">

d. HTML Font Colors:
<FONT > allows us to change the color of any portion of text. Modifying the color of a
segment of text is easy using the COLOR attribute of the font tag. For example,
<FONT COLOR = "#0000FF ">
I am going reading today
</FONT >
changes the text “I am going reading today” to blue.

The SIZE attribute of the font tag is typically used to change the font size of an
indiv idual part
of a document. For example, makes the first letter of the first paragraph slightly
larger than the rest of the text. This can be accomplished with the following code:
<FONT SIZE = "+3">W</FONT >elcome my friend.

Most browsers also support a FACE attribute for the <FONT > tag,
For example,
<FONT FACE = "Arial">New font type</FONT >

e. HTML Comments: The comment tag is not <COMMENT >; it is the set of symbols
<!--
for the beginning tag and --> for the ending tag. A comment, properly included,
does not change the appearance of your Web page. To use the comment tag, place
the comment text between the pairs of dashes in the tag. For example,
<! -- This is a comment. -->

For example,
<!—This is B.Sc III Year -->

14. De fine HTML formatting. Explain how to c reate a Hyperlink.
A. HTML Formatting a nd Hyperlink Creation:
HTML tags describe the desired structure of a Web page, rather than exactly how
it should look.

Paragraph Tag:

The paragraph tag is used to break the text into paragraphs. Most browsers
place an empty vertical space between paragraphs so they stand apart from each
other. To designate a block of text as a paragraph, enclose it within the paragraph
beginning and ending tags: <P> and </P>.
The following HTML code illustrates the use of the paragraph tag:
<P>
This is Web Technologies.
</P>

Heading Tags:
Most browsers support a hierarchy of six levels of HTML headings. The
beginning tag for heading i is <Hi>, where i can be any value f rom 1 to 6. The
corresponding ending tag, as expected, is </Hi>. The largest heading is <H1> and
the smallest is <H6>. One important attribute of the heading tag is ALIGN, which
can have values of left, center, or right.

<H1>Complete Sentences</H1>
<H2>F ragments and Run-on Sentences</H2>

Anchor Tag:
The anchor tag, <A> and </A>, is the mechanism by which hyperlinks are placed in
hypertext documents. Its syntax is more complicated than that of most other tags.
The term anchor is used because it indicates the static positioning of a hyperlink.

The three basic parts of a hyperlink are:
• The beginning and ending tag pair <A> · · · </A>.
• The HREF attribute that specifies the URL of the page to be loaded when the
hyperlink is selected.
• The text (or graphic) that appears on-screen as the active link.

Clic kable Text Hype rlinks
Consider the following example:
<A HREF = "www.yahoo.com”>Yahoo</A>
Clic kable Image Hype rlinks:
<A HREF = "http://www.yahoo.com">
<IMG SRC = "arrow.gif "
HEIGHT = "50"
WIDTH = "50">
</A>

Mailto Hyperlinks:

It is common practice to add a mailto hyperlink to a Web page.
<A HREF = "mailto:abc@yahoo.com">Contact ABC</A>

Image Tag:
The image tag, <IMG>, is used for including in-line images in HTML documents.
An example of the use of the tag is:
<IMG SRC = "wheelbarrow.gif "
ALT = "Under Construction"
HEIGHT = "50"
WIDTH = "50">

The most important attribute of the image tag is SRC, which is used to specify
the image to be displayed. Any type of image can be specified, using either a relative
or an absolute URL, where the relative URL would relate to the document in which
the image appears.
When a browser retrieves a Web page, it does not automatically get the
images that go along w ith that page. Each image must be retrieved separately. To
render the document on-screen, the browser must know the sizes of the images. On
the other hand, a browser will list image dimensions as x ×y, w here x is the WIDTH
of the image and y is the HEIGHT. The HEIGHT and WIDTH attributes can also have
percentages as values, allowing them to be used to scale an image relative to the
size of the browser’s window.