Web browsers

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Revision as of 21:02, 17 April 2017 by Mr. MacKenty (talk | contribs)
Web Science[1]

A web browser (commonly referred to as a browser) is a software application for retrieving, presenting and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier (URI/URL) that may be a web page, image, video or other piece of content.[1] Hyperlinks present in resources enable users easily to navigate their browsers to related resources.[2]

Common components of a web browser[edit]

I am grateful to Tali Garsiel and Paul Irish for releasing their EXCELLENT treatment of web browsers under creative commons. THANK YOU !

  • Address bar for inserting a URI
  • Back and forward buttons
  • Bookmarking options
  • Refresh and stop buttons for refreshing or stopping the loading of current documents
  • Home button that takes you to your home page

Overall structure[edit]

  • The user interface: this includes the address bar, back/forward button, bookmarking menu, etc. Every part of the browser display except the window where you see the requested page.
  • The browser engine: marshals actions between the UI and the rendering engine.
  • The rendering engine : responsible for displaying requested content. For example if the requested content is HTML, the rendering engine parses HTML and CSS, and displays the parsed content on the screen.
  • Networking: for network calls such as HTTP requests, using different implementations for different platform behind a platform-independent interface.
  • UI backend: used for drawing basic widgets like combo boxes and windows. This backend exposes a generic interface that is not platform specific. Underneath it uses operating system user interface methods.
  • JavaScript interpreter. Used to parse and execute JavaScript code.
  • Data storage. This is a persistence layer. The browser may need to save all sorts of data locally, such as cookies. Browsers also support storage mechanisms such as localStorage, IndexedDB, WebSQL and FileSystem.[3]

Do you understand this?[edit]

Explain the functions of a web browser

in depth video describing this content[edit]

Standards[edit]

These standards are used from the IB Computer Science Subject Guide[4]

  • Explain the functions of a browser

References[edit]

  1. http://www.flaticon.com/
  2. https://en.wikipedia.org/wiki/Web_browser
  3. https://www.html5rocks.com/en/tutorials/internals/howbrowserswork/#The_browser_high_level_structure
  4. IB Diploma Programme Computer science guide (first examinations 2014). Cardiff, Wales, United Kingdom: International Baccalaureate Organization. January 2012.