It2353 Wt Unit 1

GIT-DEPARTMENT OF COMPUTER SCIENCE AND ENGINEERING

IT2353 – WEB TECHNOLOGY

QUESTION BANK

Unit 1

Two Marks

1. Define URI. (AM 2011)

URI (Uniform Resource Identifier): It identifies an object on the Internet.

2. State the use of web server logs and list the contents of a message log. (AM 2011)

A web server log is a log file automatically created and maintained by a server consisting of a list of activities it performed.

List of Contents:

Client IP address Request date/time

Page requested

HTTP code

Bytes served

User agent

3. How will you create a password field in a HTML form? (ND2011)

Password fields are unique type of data entry fields. All information within the password field will be displayed as an asterik(*).

Password field can be created as :

<input type="password" name="<Name of the field>" value="<Default value of the object>">

4. List any four common browsers. (ND2011)

Mozilla Firefox, google chrome, safari, internet explorer, opera ….

5. State the function of DNS and the protocol used. (ND 2012)

NITHYAKANI.P UNIT-I Page 1

http://en.wikipedia.org/wiki/User_agent

http://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol

http://en.wikipedia.org/wiki/Webpage

http://en.wikipedia.org/wiki/Time

http://en.wikipedia.org/wiki/Calendar_date

http://en.wikipedia.org/wiki/IP_address

http://en.wikipedia.org/wiki/Client_(computing)

http://en.wikipedia.org/wiki/Server_(computing)

http://en.wikipedia.org/wiki/Data_logging


Domain Name Service (DNS) is the service used to convert human readable names of hosts to IP addresses. Protocols used: - TCP and UDP

6. Write HTML code to display an image. (ND 2012)

<img align="center" size="100" src="IndiaMap.jpg" usemap="#india"/>

7. State the uses of internet protocol. (AM 2012)

IP software is used to transfer data from source and destination.

IP supports unique addressing for computers on a network.

8. List and explain any two HTML elements. (AM 2012)

<HTML> </HTML> <BODY> </BODY> <FORM> </FORM> <TABLE> </TABLE> <P>, <B>, <I>, <U> <SPAN>, <STRONG>, <TT>, <LI>, <OL>, <UL> <INPUT> <SELECT>

9. Write HTML code to create the following Table (MJ 2013)w x

y z

<html><table border="1" ><tr>

<td>w</td><td>x</td>

</tr><tr>

<td>y</td><td>z</td>

</tr></html>

10. List the different basic protocol used in internet. (MJ 2013) Transmission Control Protocol (TCP) User Datagram Protocol (UDP) Internet Control Message Protocol (ICMP)

11. What do you mean by relative URLs? (MJ2014)


http://en.wikipedia.org/wiki/Internet_Control_Message_Protocol

http://en.wikipedia.org/wiki/User_Datagram_Protocol

http://en.wikipedia.org/wiki/Transmission_Control_Protocol


A Relative URL or a partial internet address, points to a resource relative to the current directory or file.

Example : <a href="Home.html">back</a>

12. Write the functions of a web server. (MJ2014)

A Web Server is software that accepts HTTP requests from web clients and returns an appropriate resource in the HTTP response.

Functions of a web server:-

Store, process and deliver web pages to clients.

Receive HTTP request via TCP

Log information about the request and response

13. Write the expansion for the following.

ARPA – Advanced Research Projects Agency UDP – User Datagram ProtocolPOP3 – Post Office Protocol version 3MIME – Multimedia Internet Message Extension Protocol IMAP – Internet Message Access Protocol

14. What are the two major protocols for accessing email from servers? (APRIL/MAY)

HTTP - Hypertext Transfer Protocol

SMTP - Simple Mail Transfer Protocol.

15. Define HTTP Protocol.

HTTP is a form of stateless communication protocol.

It gives a detailed specification of how web client and server should communicate and the basic structure followed is known as Request-Response model.

16. What are HTTP Status Codes?

This code provides the information about the HTTP Response from the server. All status code is three-digit decimal numbers. The first digit represents the general class of status code. The last two digits of a status code define the specific status within the specified



The five classes of HTTP 1.1 status codes.

17. List out the available HTTP methods.

GET, HEAD, POST, OPTIONS, PUT, DELETE, TRACE

18. What are Secure Servers?

The standard means of indicating to a browser that it should encrypt an HTTP request is to use the https scheme on the URL for the request.

For e.g. https://www.example.org will cause the browser to attempt to send an encrypted HTTP GET request.

19. What are HTML forms?

An HTML form is used to allow a user to input data on a web page and the element used is form element and its main attributes are action and method.

Its format is

<form action=”form.php”>

</form>

20. What are the types of list supported by HTML?

There are three types of list supported by HTML.

i. Unordered – A bullet listii. Ordered – a number list

iii. Definition – A list of terms and definitions for each


Digit Class

1. International2 Success3 Redirection4 Client Error5 Server Error


16 MARKS

1. Explain in detail the working of the following Internet Protocols

(i) TCP/IP (AM 2011) (ii) HTTP

TCP/IP:- [Transmission Control Protocol / Internet Protocol]

TCP is a higher level, heavy weight and Connection oriented protocol.

Used along with the Internet Protocol to send data and track packets

INTERNET PROTOCOL

Primary network protocol used on the network.

IP Address:-

An IP address is a binary number that uniquely identifies computers and

other devices on a TCP/IP network

32 bits in length

Written as four decimal numbers separated by dots.

E.g. 10.1.1.41

IP software:-

IP software is used to transfer data from source and destination.

Packet:-

– Creates a packet which is a sequence of bits along with source and destination IP

address.

Gateway:-

– Packet is sent to a gateway that connects to more than one network.

– A separate protocol (the current standard is BGP-4, the Border Gateway

Protocol) is used to pass network connectivity information between gateways

Route:-

– The sequence of computers that a packet travels through from source to

destination is known as its route

Port:-


http://compnetworking.about.com/cs/basictcpip/g/bldef_tcpip.htm


– The port allows TCP to be used to communicate with many different

applications on a machine.

FUNCTION OF TCP/IP

o Reliable data transmission

o Error detection using checksum

Limitations of IP:-

o No guarantee of packet delivery (packets can be dropped)

o Communication is one-way (source to destination)

IP ALONG WITH TCP:-

o Provides guarantee that packets delivered



o Provide two-way (full duplex) communication

(ii) Hypertext Transport Protocol (HTTP)

HTTP is a form of stateless communication protocol which gives a detailed specification

of how web client and server should communicate.

• HTTP is based on the request-response communication model:

– Client sends a request

– Server sends a response

• HTTP is a stateless protocol:

– The protocol does not require the server to remember anything about the client

between requests.

HTTP

• Normally implemented over a TCP connection (80 is standard port number for HTTP)

• Typical browser-server interaction:

– User enters Web address in browser.

– Browser uses DNS to locate IP address.

– Browser opens TCP connection to server.

– Browser sends HTTP request over connection.

– Server sends HTTP response to browser over connection.

– Browser displays body of response in the client area of the browser window.

• The information transmitted using HTTP is often entirely text.

• Can use the Internet’s Telnet protocol to simulate browser request and view server

response.


ftp://ftp.rfc-editor.org/in-notes/rfc2616.txt


2. Give the structure of HTTP request and response messages. (AM 2012), (MJ 2013) (ND

2012),(ND 2012),(ND2011), (AM 2011)

(i) HTTP REQUEST MESSAGE:-

1. Overall Structure

Every HTTP request message has the same basic structure:

Start lineHeader field(s) (one or more)Blank lineMessage body (optional)

2. HTTP Version

The initial version of HTTP was referred to as HTTP/0.9. All operational browsers and servers support HTTP/1.1 (latest version)

3. Request-URI

The Request-URI is a Uniform Resource Identifier and identifies the resource upon which

to apply the request.

TYPES of URI:-



Uniform resource locator(URL)

- Consists of a scheme, a host, and path name .

- https://mail.google.com/mail/u/0/?shva=1#inbox/141707ce154b142f

Uniform Resource Name(URN)

- consists of unique identifier name

- 141707ce154b142f is the identifier of this email (URN).

4. Request Method

5. Header Fields and MIME Types

Each header field begins with a field name, such as Host, followed by a colon and then

a field value.

White space is allowed to precede or follow the field



Value

Some Header Fields are

Accept- request header defining MIME (Multipurpose Internet Mail

extensions)

User Agent – request header specifying the type of client

From

If-Modified-Since

MIME TYPES

MIME TYPE DESCRIPTION

Text/plain Human readable text without formatting

information

Text/html HTML document

Image/jpeg JPEG encoded image

(ii) HTTP RESPONSE MESSAGE

1. Overall Structure

Every HTTP response message has the same basic structure:

Status line

Header field(s) (one or more)

Blank line

Message body (optional)

2. Response Status Line

The first line of a Response message is the Status-Line, consisting of the protocol version

followed by a numeric status code.

The five classes of HTTP 1.1 status codes.

Digit Class1 International2 Success3 Redirection4 Client Error5 Server Error



3. Response Header Fields

- Response header fields give information about the server.

Field Name Use

Date Time at which response was generated

Server Information identifying the server software

Last-Modified Time at which the resource was last modified.

Expires Time after which the client should check with the

ETag A hash code of the resource returned.

Accept-Ranges specifies the units that may be used by the client in a range request.

Location specify new URI for the requested resource.

4. Cache Control

• A cache is a local copy of information obtained from some other source

• Most web browsers use cache to store requested resources so that subsequent requests to the

same resource will not necessarily require an HTTP request/response

– Ex: icon appearing multiple times in a Web page

Character Sets

A character set defines the mapping between these integers, or code points, and characters.



A character encoding is a bit string that must be decoded into a code-point integer that is

then mapped to a character according to the definition provided by some character set.

The Accept-Charset header field

used by a client to tell a server the character sets and character encodings

Content-Type header field - used in an HTTP response would indicate that the body of the

message is an HTML document.

3. Explain the capabilities of web client and web server. (12) (MJ 2013), (AM 2012) WEB SERVER :-

A Web server is a program that, using the client/server model and the World Wide Web's

Hypertext Transfer Protocol ( HTTP ), serves the files that form Web pages to Web users

(whose computers contain HTTP clients that forward their requests).

Every computer on the Internet that contains a Web site must have a Web server program.

Two leading Web servers:

Apache , the most widely-installed Web server.

Microsoft's Internet Information Server ( IIS ).

Characteristics of a server:

It is initially passive (or slave, waiting for a query);

It is listening, ready to respond to requests sent by clients;

When a request comes, he treats it and sends a response.



Basic functionality:

o Receive HTTP request via TCP.

o Map Host header to specific virtual host (one of many host names sharing an IP

address).

o Map Request-URI to specific resource associated with the virtual host

File: Return file in HTTP response.

Program: Run program and return output in HTTP response.

o Map type of resource to appropriate MIME type and use to set Content-Type header

in HTTP response.

o Log information about the request and response.

o A web server log is a log file automatically created and maintained by a server consisting of a list of activities it performed.

List of Contents:

Client IP address Request date/time

Page requested

HTTP code

Bytes served

User agent

o Secure server: The standard means of indicating to a browser that it should encrypt an HTTP request is to use the https scheme on the URL for the request.

o For e.g. https://www.example.org will cause the browser to attempt to send an encrypted HTTP GET request.

WEB CLIENT:-

A Web Client is a program(web browser) that, using the client/server model and the

World Wide Web’s Hypertext Transfer Protocol (HTTP), requests the web pages from the web

server.


http://en.wikipedia.org/wiki/User_agent





http://en.wikipedia.org/wiki/IP_address

http://en.wikipedia.org/wiki/Client_(computing)

http://en.wikipedia.org/wiki/Server_(computing)

http://en.wikipedia.org/wiki/Data_logging


• Primary tasks:

– Convert web addresses (URL’s) to HTTP requests

– Communicate with web servers via HTTP

– Render (appropriately display) documents returned by a server

FQDN- Fully Qualified Domain Name is the website address i.e., www.google.com...

• Browser uses authority to connect via TCP

• Request-URI included in start line (/ used for path if none supplied)

• Fragment identifier not sent to server (used to scroll browser client area)

• Standard features

• Save web page to disk

• Find string in page

• Fill forms automatically (passwords, CC numbers, …)

• Set preferences (language, character set, cache and HTTP parameters)

• Modify display style (e.g., increase font sizes)

• Display raw HTML and HTTP header info (e.g., Last-Modified)

• Choose browser themes (skins)

• View history of web addresses visited

• Bookmark favorite pages for easy return

• Additional functionality:

• Execution of scripts (e.g., drop-down menus)

• Event handling (e.g., mouse clicks)

• GUI for controls (e.g., buttons)

• Secure communication with servers

• Display of non-HTML documents (e.g., PDF) via plug-ins

Web Client Logs:-

Record client activities such as

o Server address

o Response date/time

o Page accessed





http://www.google.com/


o HTTP code

o URI

o Bytes received

4. State the types of lists supported by HTML and explain them in detail. (AM 2011)

or

Explain the purpose and way of creating lists in HTML documents. (8) (ND2011)

HTML LIST

HTML offers three ways to specify the lists of information.

All lists must contain one or more list elements.

Types of List1. Unordered Lists, 2. Ordered Lists 3. Description Lists

HTML List Tags

Types of List Starting Tag Ending Tag Description

Unordered <ul> </ul> Defines an unordered list

Ordered <ol> </ol> Defines an ordered list

Definition or

Description

<dl> </dl> Defines a description list

<dt> </dt> Defines the term in a description list

<dd> </dd> Defines the description in a description list

<li> </li> Defines a list item

Unordered HTML Lists

An unordered list starts with the <ul> tag and ends with </ul> tag.

Each list item starts with the <li> tag.


http://www.w3schools.com/tags/tag_li.asp

http://www.w3schools.com/tags/tag_li.asp

http://www.w3schools.com/tags/tag_dd.asp


http://www.w3schools.com/tags/tag_dt.asp


http://www.w3schools.com/tags/tag_dl.asp


http://www.w3schools.com/tags/tag_ol.asp


http://www.w3schools.com/tags/tag_ul.asp




Unordered HTML Lists - The Style Attribute

A style attribute can be added to an unordered list, to define the style of the marker:

Style Description Symbol

<ul type="disc"> The list items will be marked with bullets (default) ●

<ul type="circle"> The list items will be marked with circles ○

<ul type="square"> The list items will be marked with squares ■

Example:- The list items will be marked with bullets (small black circles).

HTML Script Display in a Web Page

<!DOCTYPE html><html>

<body>

<h2>Unordered List with Default bullets </h2> <ul>

<li>Apples</li> <li>Bananas</li> <li>Lemons</li> <li>Oranges</li>

</ul>

</body></html>

Unordered List with Default Bullets

Apples Bananas

Lemons

Oranges

Ordered HTML Lists

An ordered list starts with the <ol> tag and ends with </ol> tag. Each list item starts with the <li> tag.

The list items will be marked with numbers.

A type attribute can be added to an ordered list, to define the type of the marker:

Type Description Symboltype="1" The list items will be numbered with numbers (default) 1. 2. 3.type="A" The list items will be numbered with uppercase letters A. B. C.type="a" The list items will be numbered with lowercase letters a. b. c. type="I" The list items will be numbered with uppercase roman numbers I. II. III.type="i" The list items will be numbered with lowercase roman numbers i. ii. iii.

Example for Ordered List




<!DOCTYPE html><html><body>

<h2>Ordered List</h2><ol>

<li>Apples</li> <li>Bananas</li> <li>Lemons</li> <li>Oranges</li>

</ol> </body>

</html>

Ordered List

1. Apples2. Bananas

3. Lemons

4. Oranges

HTML Description Lists

A description list is a list of terms, with a description of each term. The <dl> tag defines a description list and ends with </dl>

The <dt> tag defines the term (name), and the <dd> tag defines the data (description).


<!DOCTYPE html><html><body> <h2>A Description List</h2>

<dl> <dt>Coffee</dt> <dd> - black hot drink </dd> <dt>Milk</dt> <dd> - white cold drink <dd>

</dl></body> </html>

A Description List

Coffee- black hot drink

Milk- white cold drink

5. Explain how tables can be inserted into a HTML document with an example.

TABLES:-

The HTML tables allow users to arrange data into rows and columns of cells.

The HTML tables are created using the <table> tag in which the <tr> tag is used to create table rows and <td>

tag is used to create data cells.

Table elements Starting Tag Ending Tag Description

table <table> </table> defines a table

caption <caption> </caption> gives the table caption







tr <tr> </tr> defines a row in a table

th <th> </th> defines a header cell

Td <td> </td> defines the data in the table cell

HTML Script File name: eligibility.html Display in a Web Page

!DOCTYPE HTML><html> <head><title>Campus Recruitment Program 2014-2015 </title></head> <body> <table border="1"> <caption><h3><b> Eligibility criteria for Students <b> </h3> </caption> <tr> <th> Degree </th> <th>Percentage / CGPA</th></tr> <tr> <td>X</td> <td>60%</td></tr> <tr><td>XII</td> <td>60%</td></tr> <tr> <td>B.TECH</td> <td>68% / 6</td> </tr> <tr> <td>M.TECH</td> <td>68% / 6</td> </tr> </table> </body> </html>

Table Attributes:

Table Attributes Format Eg.

Border border=”value” border=”1”

Cell padding (space btw cell and the wall) cellpadding=”value” cellpadding=”2”

Cell spacing (space btw cells) cellspacing=”value” cellspacing=”2”

Row span (merge the rows) rowspan=”value” rowspan=”3”

Col span (merge the cols) colspan=”value” colspan=”3”

FORMS:-









A form will take input from the user and then will post it to a back-end application such as CGI,

ASP Script or PHP script etc.

The back-end application will perform required processing on the passed data based on defined

business logic inside the application.

E.g.: online banking, online purchasing, online registration etc.

Form

elements

Starting Tag Ending Tag Description

Form <form> </form> defines the form

Input < input > - Get the input from the user

Select <select> </select> Defines the drop down list

Option <option> </option> Defines the option to select

INPUT TAG

ATTRIBUTESType Description

Text type=”text” Defines normal text input

Radio type=“radio" Defines radio button input (for selecting one of many choices)

Submit type=”submit” Defines a submit button (for submitting the form)

Password type=”password” Defines password. Masks the character as user enters

Checkbox type=”checkbox” Defines a checkbox button(for selecting one of many option)

Html Script : Filename- reg form.html Display in a web page










<!DOCTYPE HTML><html><head><title>REG FORM</title></head><body><h4>Student Info</h4><FORM>Student Name:<input type="text" width="20"><br>Batch:<select><option type="" value="2012 to 2016"> 2012 – 2016 </option><option type="" value="2011 to 2015"> 2011 – 2015 </option></select><br><br><br>CGPA:<select><option type="" value="10"> 10 </option><option type="" value="9"> 9 </option><option type="" value="8"> 8 </option><option type="" value="7"> 7 </option><option type="" value="6"> 6 </option></select></form></body></html>



6. Explain the use of relative URL’s with an example.

o A relative URL doesn’t contain any protocol or machine information.

o Its path generally refers to a resource on the same machine as the current document.

o Relative URLs may contain relative path components (".." means one level up in the

hierarchy defined by the path), and may contain fragment identifiers.

o Relative URLs are resolved to full URLs using a base URL.

As an example of relative URL resolution:

MAIN HTML PATH:

file:///C:/Users/SYS1/Desktop/Interview.html

The relative URL in the following markup for a hypertext link:

<img src="git.png"> expands to the image contained in the URL “git.png”

<a href="eligibility.html">Eligibility Criteria</a> expands to the html file contained in the URL

“eligibility.html”

Html Script File name: interview.html Display in a Web Page

<!DOCTYPE html><html><head><title>GIT INTERVIEW</title></head><body><img src="git.png"><H4><b><u>Links Regarding Campus Interview <u></b></h4><ul><li> <a href="eligibility.html">Eligibility Criteria </a></li><li><a href="reg form.html">Registration Form</a> </li></ul></body></html>



7. How do you create frames? Why do we need them? Develop an application to explain the same.

FRAMES

Frames is used to display more than one HTML document in the same browser window.

Each HTML document is called a frame, and each frame is independent of the others.

Elements of Frames:

1. The Frameset Tag

The <frameset> tag defines how to divide the window into frames.

Each frameset defines a set of rows or columns.

The values of the rows/columns indicate the amount of screen area each

row/column will occupy.

Format:

<frameset cols=”25%,25%,50%”>

2. The Frame Tag

The <frame> tag defines what HTML document to put into each frame.

Html Script File name: Frames.html Display in a Web Page

<!DOCTYPE html>

<html>

<frameset rows="50%,50%">

<frame src="Eligibility.html">

<frame src="reg form.html">

</frameset>

</html>



Html Script for Frame Sources:-

<frame src="Eligibility.html"> <frame src="reg form.html">

!DOCTYPE HTML><html> <head><title>Campus Recruitment Program 2014-2015 </title></head> <body> <table border="1"> <caption><h3><b> Eligibility criteria for Students <b> </h3> </caption> <tr> <th> Degree </th> <th>Percentage / CGPA</th></tr> <tr> <td>X</td> <td>60%</td></tr> <tr><td>XII</td> <td>60%</td></tr> <tr> <td>B.TECH</td> <td>68% / 6</td> </tr> <tr> <td>M.TECH</td> <td>68% / 6</td> </tr> </table> </body> </html>

<!DOCTYPE HTML><html><head><title>REG FORM</title></head><body><h4>Student Info</h4><FORM>Student Name:<input type="text" width="20"> <br>Batch:<select><option type="" value="2012 to 2016"> 2012 – 2016 </option><option type="" value="2011 to 2015"> 2011 – 2015 </option></select><br><br><br>CGPA:<select><option type="" value="10"> 10 </option><option type="" value="9"> 9 </option><option type="" value="8"> 8 </option><option type="" value="7"> 7 </option><option type="" value="6"> 6 </option></select></form></body></html>

The disadvantages of using frames are:

The web developer must keep track of more HTML documents. It is difficult to print the entire page.


Documents

It2353 Wt Unit 1