3.4 Web Technologies Flashcards
What is the purpose of HTML?
Allows a browser to render a webpage by describing the structure and layout of the webpage. Defines the contents of the web page using elements that are put in between <>.
What is a class/identifier and what is the difference?
A HTML attribute given to an element allowing it to be specifically styled in CSS.
Classes can be given to multiple elements whereas IDs are unique to an element.
What is the purpose of CSS?
Describing the style of a web page. Specifies the way that html elements look. Uses # to select IDs and . to select classes.
What is JavaScript?
An interpreted scripting language used to add interactivity to web pages.
What are the advantages of using JS?
client computer can validate input data before sending it to server
eases the load on busy servers
reduces web traffic
What is a search engine?
A program that searches through a database of IP addresses looking for resources based on criteria set by a client.
Why are search engine results indexed?
So that the most high quality and relevant websites are displayed at the top of the page.
What is used to index web pages?
web crawlers/spiders
How do web crawlers work?
Traverse the internet web page by web page using links to travel between sites. At each web page, it takes each word and adds an entry for the page in the index under that word.
What factors does the pagerank algorithm depend on?
how many incoming links a web page has from other websites
the page rank of the web pages that link to this website
how long the web page has existed
the amount of relevant content on the web page
the number of links to high page rank websites
What is the damping factor?
A value between 0 and 1 that represents the probability that a user will not follow a link.
What is the difference between server-side and client-side processing and give a language that uses each?
Server side processing is when a client sends data to the server to process it e.g. SQL or PHP
Client side processing is when data is processed on the local computer e.g. JavaScript
What are the advantages of server side processing?
server has larger processing power than clients so can perform large calculations
not browser dependent
more secure
What are the advantages of client side processing?
web page is more responsive on the user end
instructions are executed quicker
developers have more control over the behaviour of the website
