web technologies

• Internet


  A network of networks, connecting billions of mobile devices, laptops, microcomputers, minicomputers, mainframes and supercomputers linked in commercial, government and educational networks
• Businesses set up websites on the Internet

  • They can advertise what they do and what they sell
  • People can email enquiries, orders and requests
  • They can reach an international audience
• Main services provided by the Internet

  • Electronic mail (email)
  • Data exchange
  • Instant messaging
  • World Wide Web (www)
  • File transfer protocol (FTP)
• Email


  A method of communication between computers on a network, where messages can be sent 'electronically' using special software from one computer to another anywhere in the world, via networks such as LANs and WLANs. The mail is then kept in an electronic mailbox.
• Data exchange


  Sending data to another computer (uploading) or receiving data from a computer (downloading)
• Instant messaging


  A feature that allows users who are connected to the Internet at the same time to exchange text, images, video or audio messages in real time
• World Wide Web (www)


  The main way of accessing information on the Internet, based on pages of information which are linked and viewed by a web browser
• File transfer protocol (FTP)


  A protocol for the transfer of files across the Internet, where files are made available on thousands of the Internet's computers for downloading onto individual computers
• Ways to connect to the Internet

  • Modem, router and/or switch connected to a telephone line
  • Network interface card (NIC) or network adapter
  • Software on your computer or mobile device (such as a web browser and email package)
  • Internet service subscription with an Internet service provider (ISP)
• Modem


  Provided by your ISP to convert analogue and digital signals between your landline and the Internet
• Router


  The 'traffic cop' of a network, directing data from the modem and sending it to the different devices that are connected to it
• Switch


  Expands the number of devices that can be connected to a router
• Network interface card (NIC) or network adaptor

  Hardware that provides the computer with a dedicated connection to a network, for wired or wireless connections
• Web browser


  A software application that allows you to access resources and websites on the Internet
• Types of Internet services

  • Dial-up
  • DSL (broadband or cable)
  • Wireless (3G or 4G) for mobile devices
• Dial-up


  The slowest way to connect to the Internet, requiring use of a landline telephone
• Broadband


  A faster method using a digital subscriber line (DSL) service, allowing use of the phone while connected to the Internet
• Cable


  A broadband service using a cable modem to send and receive digital data through a connection to a fibre optic cable television system
• 2G, 3G and 4G-LTE


  Generations of mobile phone systems used to connect to the Internet, with 4G-LTE providing significantly faster speeds and increased network coverage
• TCP/IP (transmission control protocol/Internet protocol)


  The set of rules for sending and receiving data over the Internet, breaking down data into packets and reassembling it
• Host (server) computer


  A computer on the Internet that provides services such as email, news or data to other computers, identified by a unique IP address
• Domain name


  An easier to remember address for a website, which is translated to the IP address behind the scenes
• URL (uniform resource locator)

  The address of a site on the Internet, entered into a web browser to access the site
• Components of a URL

  • // (double slash) - path to the computer (server)
  • http - hypertext transfer protocol
  • ftp - file transfer protocol
  • .com - commercial organisation
  • .uk - United Kingdom
  • .edu - university
  • .bb - Barbados
  • .org - organisation
  • .gov - government
  • .net - network
  • .html or .htm - file extension
• Web browser


  Software application that allows you to access and view web pages on the internet
• Address bar


  Space at the top of the screen where you enter the URL (web address)
• Example URL


  • www.nationnews.com
• URL

  Web address that identifies the location of a web page or resource on the internet
• Components of a URL

  • http:///
  • http
  • //
  • Web server name
  • Folder location
  • File name
• http


  Hypertext transfer protocol - set of rules used to display web pages
• ftp


  File transfer protocol - allows transfer of files across the internet
• Top-level domain extensions

  • .com
  • .uk
  • .edu
  • .bb
  • .org
  • .gov
  • .net
• .html or .htm


  Indicates a web page file
• Most browsers don't require typing 'http://' - just 'www' and the rest of the address
• Web server


  Computer that uses special software to transmit web pages over the internet
• Web server names are often prefixed with 'www'
• Homepage


  Title page of a website that links to other related pages
• The web is an information retrieval system that enables users to connect from one website to another via hypertext links
• Search engine


  Software application that finds websites using keywords
• Search engines index the words on billions of web pages using software robots (spiders)