Web Applications

Web Applications

1. THE WWW

   • WWW is a SYSTEM of hyperlinked documents
     • That are accessed via the internet using a browser

2. The INTERNET

   • a GLOBAL computer network c
     • Consisting of interconnected networks using communication protocols

3. URL

   • uniform resource locator
   • Unique address
   • Idenifying every resource on the internet

4. TCP "TRANSMISSION CONTROL PROTOCOL LAYER

   • TCP layer consists of two hosts
     • In order to establish a connection and EXCHANGE DATA
   • The TCP layer is responsible for reliability and delivery
   • TCP layer converts a message in to "DATA PACKETS"
   • These DATA PACKETS contain
     • Header / sequence number and DESTINATION ADDRESS
   • These DATA PACKETS are transferred over a network to the DESTINATION ADDRESS computer
   • The DATA PACKETS then REASSEMBLE so that the message can be read by a recipient

5. IP LAYER

   • IP layer is responsible for ROUTING data packets from node to node
   • it forwards each data packet using its address number (ip number)
   • Packets of the same message may be sent via different routes
     • By routers or switches

6. HTML (HYPER TEXT MARKUP LANGUAGE)

   • Features of HTML
     • HTML is a language / has a syntax
     • HTML IS A FILE CREATED FOR EACH AND EVERY WEBPAGE
     • HTML command take the form of TAGS
       • HEAD TAG / describes and identifies the website page
         • BODY TAG/ specifies the content of the web page (what will be displayed on the web browser)
     • Text can be formatted (font sizes colour)
       • Multimedia content can be inserted (VIDEOS IMAGES SOUNDS)
     • Links can be inserted to other pages
     • HTML is a pseudo programming language
       • HTML can be used to create and edit webpages
         • HTML can be used to set the properties of a webpage
           • Using tags such as <head> <body>
             • Using tags you can insert multimedia elements (sounds, images,video)
               • Using tags you may edit the layout of the webpage
                 • You may also create templates sheets for consistency on a number of your webpages
                   • You may insert hyperlinks to naviagate from one page to the other
   • How HTML is used to create a website
     • HTML is a pseudo programming language
     • HTML is used to edit and create webpages
     • HTML tags such as BODY HEAD can be used to implement multi media into your webpage
     • HTML tags can be used to edit the layout of your webpage
       • Allowing you to create template sheets for your website in order to create consistency across your webpages
     • HTML can also include hyperlinks/navagation buttons/menus to enable the user to navagate from one page to the other
     • CSS templates may be used

7. Typical web browser

   • Features
     • Web browser allows web pages to be viewed
       • By converting HTML doucmnets into multi media display
     • Web browser provides a navagation/home page/tabs/hyperlinks
     • Webbrowser also includes a search engine
       • As well as a URL address BOX
     • WEB BROWSER also includes records of HISTORY BOOKMARKS FAVOURTIES
     • web browser plugins can also be added
     • Security levels / filters can be applied

8. SEARCH ENGINE

   • Features
     • The user keys in key words / phrases
       • representing the search criteria
     • A list of appropriate websites will appear in order of relevance / popularity
     • The user can also broaden the search using
       • AND /OR/NOT
     • The search results can be restricted to news / images/regions