Extranet, Intranet & Internet (CIE IGCSE ICT)

• The Internet is a very large global network that consists of many other interconnected networks
• The world wide web is the vast collection of web pages that can be accessed using a web browser
• The world wide web allows you to access information by using the internet

Characteristics of the Internet

• Open
  • The Internet is an open network meaning anyone with access can access the same resources and information as everybody else 
• Decentralisation
  • The Internet is a decentralised network with no owner, controller or governing body.  Instead, it is made up of vast numbers of interconnecting networks that operate independently but work together to provide communication
• Global Reach
  • The internet is a global network meaning that people from all over the world can communicate with each other in real-time
• Accessibility
  • The Internet is available to anyone who has a suitable device and access to any one of the interconnected networks 

The Internet has many uses and plays a critical role in our lives. This can include;

• Education and training
• Social Networking
• Online shopping
• Entertainment

• Intranets operate in a similar way to the Internet and although they are still networks, they are usually private and are used to send information securely and safely 
• Unlike the Internet which is a global network accessible by all, access to an organisation’s Intranet is restricted and only accessible to authorised users such as employees

• Intranets have many advantages over the internet such as:
  • Better bandwidth than the internet
  • Data is kept within the organisation
  • Less chance of hacking and attacks
  • Administrators can manage access to external sites and links

Characteristics of an Intranet

• Private
  • An intranet is a private network that is accessible to employees within a company or organisation
• Security
  • An intranet is usually behind a firewall to ensure security and that only authorised users can access it
• Sharing and Communication
  • An Intranet allows for document sharing and the use of collaboration tools between users. It can also allow the use of email and video calling to enable efficient communication within the organisation 
• Customisation
  • An intranet can be customised to meet the specific requirements of the business such as navigation and subject content as well as the service being able to be scaled up as the business grows
• Users will require a username and password to access the Intranet

• An extranet is a private Intranet that also allows access by selected parties that reside outside of the organisation. These parties, for example, maybe customers, key stakeholders or clients
• External users will have an authorisation level once they have successfully logged in which will determine which resources they may access

• Similarities between the Internet, Intranet and extranet are as follows:
• They are all web based technologies
• They allow users to access information remotely
• They all use client server architecture
• They all use security measures such as authentication and encryption
• They all promote and facilitate information and resource sharing
• Differences between the internet, intranet and extranet are as follows:
• The internet is a global network whereas an intranet/extranet is a private network contained within an organisation
• The use of the internet covers a wide range of purposes whereas an intranet/extranet is designed for specific users and purposes
• Much of the information is publicly available whereas an intranet/extranet is not
• The internet is not owned solely by one person or organisation whereas intranets/extranets are owned usually by the organisation