1.3.3 PART 3 HTML, CSS, PageRank Flashcards
What is HTML?
Hypertext markup language
The standard markup language for web pages, that uses tags to specify the page’s elements;
HTML features?
The language of the WWW
NOT a programming language
Describes web page content
Requires a text editor and a web browser to write in HTML
Rendering?
The process of processing the HTML for display purposes
HTML Code?
Uses <tags> to govern how to present sections of content</tags>
Stores locations of images to be displayed
Provides the locations of other websites, that are linked- using hyperlinks
Common tag types?
Paragraph
Ordered lists- creates a block that needs list item tags for each line
Division tags
Hyperlink reference tags (<a> and </a>)
Image (<img></img>)
Bold and Italic
Division tags?
Create tidy blocks of HTML content that can be formatted collectively and independently using CSS.
Identifiers?
Unique to one element per webpage- allowing the element to be styled
Classes?
Can be used to identify multiple elements per page- allowing the all elements to be styled at once.
Content of a page vs style of a page?
HTML- defines page content and structure; webpages consist of a head and a body
CSS- used to define page styles and appearance
3 CSS types?
Inline Styling
Internal Embedded styling
External styling
Inline styling?
Applying style rules within a html tag
Internal Embedded styling?
Applying style rules within style tags in the <head> section
External styling?
Linking an external style sheet from any HTML file that may be created for an entire website.
Styles on one stylesheet can be applied to multiple HTML files- throughout a website- so long as the files link to it
CSS Box Model?
A container that contains multiple properties including borders, margin, padding, and the content itself; even if this is invisible.
It is used to create the design and layout of web pages.
Head of a webpage vs body of a webpage?
Head- contains page metadata
Body- contains page content
Metadata?
Data about data.
Meta tags describe the content of a webpage- can be placed inside HTML pages to make the page more likely to be found;
These tags are hidden from users, but discoverable by WEB CRAWLERS
Search engines?
Systems that locate resources on the WWW;
Keeping indexes
Index?
A record of the resources located on the WWW- updated by web crawler software
Web Crawlers?
Internet bots that endlessly scout the web to discover + record publicly available webpages.
They follow hyper links on discovered pages onto proceeding pages
What do web crawlers keep an index of?
URL of found resource
Content of the found resource
The last time the found resource was updated
Quality of the found resource
How do web searches work?
Web crawlers search the web, locating resources
Resource data is copied to the search engines index
When a client searches…
User enters search item into search engine
Index is searched for relevant content- using the PageRank Algorithm
Search results are returned to the user, displaying relevant webpages
What is PageRank?
An algorithm developed to list search results in order / rank of usefulness and relevance.
Created by Google Founders.
The page with a higher rank is a more authoritative source.
PageRank factors?
Domain name
Frequency of search term in the page
Age of the webpage
Frequency of page updates
Magnitude of content updates
Keywords in <h1> tags
PageRank Algorithm Formula?
(1-d) + d[ PR(Ti) / C(Ti) +…… + PR(Tn) / C(Tn) ]
Where:
d = damping factor
Ti and Tn= pages which link to page A
C = Number of outbound links on page Ti or Tn
How is a PageRank value calculated?
Formula must be repeated for several iterations of running the formula
Each iteration produces a more accurate PageRank value
The higher the value, the more relevant the page
A page with more inbound links will have a higher value
