1.3 Web Technologies

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Created by
Kirsty Roberts

Cards (30)

  • Cascading Style Sheets (CSS)
    • Style language used to define the layout, design and presentation of a webpage written in a markup language
  • Client-Side Processing
    • data processing and operations performed by client
    • validating data before sent to the server in order for further validation
  • HyperText Markup Language HTML
    A markup language used to write contents of webpages on the World Wide Web
  • JavaScript
    Interpreted OOP programming language used to create interactive elements within web browsers
  • Page Rank Algorithm
    • Algorithm developed by Google to rank websites in search results
    • Ranked based on usefulness, quality and importance
    • This is by counting number of links to that webpage
  • Search Engine Indexing
    • program that searches through a ​database of internet addresses​ looking for resources based on a criteria set by the client. 
  • Server-Side Processing
    • data processing and operations performed by the webserver
    • data sent from client's server to the web server for secure processing
    • output sent back to client
    • e.g python, php, java
  • Advantages of Server-side processing:
    • more secure
    • does not require plugins
    • can perform larger calculations faster than clients
    • not browser dependent
  • Advantages of Client-Side Processing:
    • executes quickly
    • webpage can immediately respond to user's actions
    • gives developers more control over how the website looks and behaves
  • Advantages of JavaScript:
    1. eases load on busy servers
    2. reduces web traffic
    3. local computer deals with invalid data before its sent off to servers
  • HTML Tags
    <html>
    <body>
    <link>
    <head>
    <title>
    <h1> <h2> <h3>
  • HTML example
  • HTML example
  • Adding Images in HTML
  • Ordered Lists in HTML
  • HTML:
    • the language/script that web pages are written in
    • allows a browser to interpret and render a webpage for the viewer by describing the structure and order of the webpage
    • 2 sections of a webpage : body and head
    • head contains title of the webpage
    • body contains the content of webpage
  • Classes and Identifiers
    • attributes which are given to elements on a webpage which you wish to style
    • multiple elements across web pages can be assigned to certain classes which means elements can follow a consistent styles and the style/formatting only has to be defined once
    • this can be defined within the head of a webpage or within a linked CSS style sheet
    • Classes are defined using a full stp
  • Example of using a Class in HTML
  • Identifiers
    • unique names given to an element on a web page whereas a class name can be used by multiple elements
    • only 1 element can be associated with a particular identifier
    • defined using a hashtag #7
  • CSS (Cascading Style Sheets)
    • a language used to describe the style of a webpage
    • used to specify the way HTML elements look
    • internal/embedded CSS is placed inside the style tags and entered directly into the HTML directly
    • Meanwhile external CSS is written in a separate document and a link to this style sheet is added to the HTML document
  • Whenever an external style sheet is used, the following link is added to the header.
  • Writing CSS
    • each section of CSS begins with the name of the class/identifier to be styled, following by a set of {} within which the elements are defined
  • JavaScript
    • scripting language which exists to add interactivity to websites
    • interpreted rather than compiled which means web pages are interpreted by the browser each time they are loaded
    • often used to validate input data on the client computer
  • Advantages of using JavaScript:
    • local computer can deal with invalid data before it is sent off to the servers
    • eases the load on busy servers
    • reduces web traffic
  • Inputs from HTML forms can be retrieved from a webpage and handling using JavaScript
  • Search Engines
    • a program that searches through a database of internet addresses
    • search engines rely on index of web pages
    • web crawlers (spiders) are used to collect information about websites to build this index.
  • Web Crawlers (spiders)
    • work by traversing the internet webpage by webpage using links on websites.
    • they collect keywords and phrases from the linked web pages and add this info to the index.
    • they also collect and add meta data from website which is the info specified by the website owner
  • PageRank Algorithm
    • ranks web pages, determining the order in which web pages are displayed when a search is conducted
    • higher ranked pages show up first
    • 2 factors which determine the page rank of a page:
    1. How many incoming links it has from other web pages
    2. The page rank of the web pages that link to it
  • Server Side Processing
    • client sends data to a server for it to be processed
    • this means no info is processed on the client computer
    • common languages - SQL, PHP
    • Used because:
    • doesn't require plugins
    • can perform large calculations much faster than clients
    • not browser dependent
    • more secure
  • Client side Processing
    • when a client processes the data on a local device
    • means all information is processed on the client computer
    • uses languages like JavaScript
    • Used because:
    • webpage can immediately respond to user actions
    • executes quickly
    • gives developers more control over the behaviour and look of the website