1.3.4 Flashcards
What information does a web crawler capture when it visits a site?
Records key information:
- Text
- Metatags
- Position of each word within the page
- Outbound Links
Follows links to other sites
The robots.txt file can be used to instruct web crawlers to skip the page.
How does a web crawler find a website?
A site is found either by selecting it from an existing list or following a link from another site.
Where does the information go that was gathered by the web crawler?
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.
What are the main factors taken into account to calculate the PageRank of a website?
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.
- The number of sites that link to the site
- The PageRank of the linking sites
- The number of outward links from the site
What the the PageRank damping factor?
A value between 0 and 1.
The probability that a user will not follow a link
What is the purpose of
HTML | CSS | JavaScript
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
What three methods can be used to insert CSS into a webpage?
Inline - CSS is added directly into the tag.
Embedded – The CSS is added to the top of each HTML page.
External – All of the CSS is added to an external file and then linked to within each HTML page
List the 9 CSS formatting commands that you are expected to know.
background-color
border-color
border-style
border-width
color (font)
font-family
font-size
height
width
What is the purpose of the div tag?
To group a section of HTML code together so they can be refered to as one identifier.
What is the purpose of the title tag, and where does it appear?
HELLO WORLD
This would appear in the tab name at the top of the web browser.
How do you get JavaScript to show an alert box?
alert(“Message to alert”)
What is server-side processing?
Which language studied is an example?
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: SQL
What is client-side processing?
Which language studied is an example?
Processing takes place in the web browser.
It does not require data to be sent back and forth meaning the code is much more responsive.
Example: JavaScript
What are the pros and cons of server-side processing?
+ 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.
What are the pros and cons of client-side processing?
+ 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.
