1.3.4 - Web Technologies

Question 1

What information does a web crawler capture when it visits a site?

Answer 1

Records key information:

• Text
• Metatags
• Position of each word within the page
• Outbound Links

Follows links to other sites

Question 2

How does a web crawler find a website?

What can a developer do stop a web crawler from indexing a site?

Answer 2

A site is found either by selecting it from an existing list or following a link from another site.

The robots.txt file can be used to instruct web crawlers to skip the page.

Question 3

Where does the information go that was gathered by the web crawler?

Answer 3

• All information gathered is stored in an index
• Data is organised and interpreted by the search engine’s algorithm to measure its importance compared to similar pages.
• Servers based all around the world allow users to access pages from the index almost instantaneously.
• Users are not searching on the web, they are searching in the search provider’s index.

Question 4

What is PageRank and what are the main factors taken into account to calculate the PageRank of a website?

Answer 4

PageRank is a calculation, which evaluates the quality and quantity of links to a webpage to determine a relative score of that page’s importance and authority on a 0 to 10 scale. Stored as a weighted, directed graph.

• The number of sites that link to the site
• The PageRank of the linking sites
• The number of outward links from the site

Question 5

What is the PageRank damping factor?

Answer 5

A value between 0 and 1.

The probability that a user will not follow a link

Question 6

How can a website improve its PageRank Score?

Answer 6

• Use meta tags (describes the content of the webpage)
• Use a lot of relevant keywords in the text of pages and in headings
• Increase the number of quality incoming links from sites with a higher rank than them
• Increase the number of outgoing links

Question 7

What is the purpose of
HTML | CSS | JavaScript

Answer 7

• HTML - Used to define the content and structure of a web page. Uses tags.
• CSS - Sets the formatting of the website (colours, layout etc.) Enables a consistent look to every page as style sheet is shared.
• JavaScript - Adds the interactivity to pages. As well as validation on web forms

Question 8

What three methods can be used to insert CSS into a webpage?

Answer 8

• Inline - CSS is added directly into the tag.
• Embedded – The CSS is added to the top of each HTML page.
• External – All the CSS is added to an external file and then linked to within each HTML page

Question 9

List the 9 CSS formatting commands that you are expected to know.

Answer 9

• background-color
• border-color
• border-style
• border-width
• color (font)
• font-family
• font-size
• height
• width

Question 10

How is a class identified in HTML and CSS?

Answer 10

Question 11

How is an ID identified in HTML and CSS?

Answer 11

Question 12

What is the purpose of the div tag?

Answer 12

To group a section of HTML code together so they can be referred to as one identifier.

Question 13

What would be the HTML code to create a bullet point list with the values “Hello” and “World” in the list?

Answer 13

Question 14

What would be the HTML code to create a numbered list with the values “Hello” and “World” in the list?

Answer 14

Question 15

What HTML tags are used to embed JavaScript in an HTML page?

Answer 15

Question 16

What HTML tags are used to embed CSS in an HTML page?

Answer 16

Question 17

How would I add a link to the BBC home page using HTML code?

Answer 17

Question 18

How would I add a 100x100 image called “smile.png” to an HTML page and set appropriate alternative text?

Answer 18

Question 19

What is the HTML code to add a form to a page with a text box and a submit button?

Answer 19

Question 20

What are the three largest headings in HTML?

Answer 20

Question 21

What is the purpose of the title tag, and where does it appear?

Answer 21

This would appear in the tab name at the top of the web browser.

Question 22

How do you get JavaScript to show an alert box?

Answer 22

alert(“Message to alert”)

Question 23

How do you capture the input from a form textbox using JavaScript?

Answer 23

passcode = document.GetElementById(“nameOfID”).value

Question 24

How do you update an element in an HTML element using JavaScript?

Answer 24

document.GetElementById(“nameOfID”).innerHTML = “Hello World”

Question 25

How do you write a **WHILE** loop in **JavaScript**?

Answer 25

Question 26

How do you write an **IF** statement in **JavaScript**?

Answer 26

Question 27

How do you write a **function** in **JavaScript**?

Answer 27

Question 28

What is **server-side processing**? Where might it be used? Which language studied is an example?

Answer 28

* Processing takes place on the web server. * Data is sent from the browser to the server, and the server processes it and sends the output back to the browser. * It is often used for generating content. It can be used to access data; including secure data. **Example language: SQL**

Question 29

What is **client-side processing**? Which language studied is an example?

Answer 29

Processing takes place in the web browser **Example language: JavaScript**

Question 30

What are the pros and cons of **server-side processing**?

Answer 30

(+) Takes away the reliance on the browser having the correct interpreter. (+) Hides the code from the user, protecting copyright and avoiding it being amended. (-) Puts extra load on the server. This is at the cost of the company hosting the website.

Question 31

What are the pros and cons of **client-side processing**?

Answer 31

(+) Does not require data to be sent back and forth meaning the code is much more responsive. (-) Code is visible which means it can be copied. (-) The browser may not run the code because it does not have the capability or because the user has intentionally disabled client-side code.

Question 32

Why check data on the client side **AND** the server side?

Answer 32

* The check is carried out client-side in the browser meaning data can be checked and stopped before reaching the server, reducing unnecessary load on the server. * JavaScript can, however, be amended and circumvented therefore address must be checked at the server to ensure this has not happened.