=>Internet :

  • The Internet is a global wide area network that connects computer systems across the world. 
  • It supports human communication via social media, electronic mail (e-mail), “chat rooms,” newsgroups, and audio and video transmission and allows people to work collaboratively at many different locations.
  • Sometimes referred to as a “network of networks,”.
  • The Internet emerged in the United States in the 1970s but did not become visible to the general public until the early 1990s. 
  • By 2020, approximately 4.5 billion people, or more than half of the world’s population, were estimated to have access to the Internet. 
  • Mobile devices, such as tablets and smartphones, make it possible for people to be connected to the Internet at all times. 
  • In order to connect to the Internet, you must have access to an Internet service provider (ISP), which acts the middleman between you and the Internet. 
  • When you connect to the Internet using a public Wi-Fi signal, the Wi-Fi router is still connected to an ISP that provides Internet access. 
  • It supports human communication via social media, electronic mail (e-mail), “chat rooms,” newsgroups, and audio and video transmission.


=>The Internet provides different online services. Some examples include:

• Web – a collection of billions of webpages that you can view with a web browser 
• Email – the most common method of sending and receiving messages online 
• Social media – websites and apps that allow people to share comments, photos, and videos 
• Online gaming – games that allow people to play with and against each other over the             Internet 
• Software updates – operating system and application updates can be downloaded from the     Internet.

=>Intranet:

  • The intranet generally looks like a private version of the Internet. 
  • Intranet can be defined as a private network used by an organization.
  • The primary purpose of an intranet is to help employees securely communicate with each other. 
  • Intranet is defined as private network of computers within an organization with its own server and firewall. 
  • Firewall software is essential to the security of an organization's intranet; it stands between the outside Internet and the private intranet.





  • Modern intranets use social features that allow employees to create profiles and to submit, like, comment, and share posts. 
  • Intranets increase communication within an organization by allowing employees to easily access important information, links, applications and forms as well as databases that can provide company records. 
  • An employee who wants to access the intranet must have a special network password. 
  • Information on an intranet is limited and only available to users with authorized access to the intranet network..

➢ Advantage of an intranet

1) It can help employees to quickly find and view information relevant to their roles and             responsibilities.
2) It can help organizations to make more information available to employee on a PULL           basis rather than email.
3) It is powerful tool for communication within an organization.

=>Extranet 

  • An extranet is a private network that uses Internet to securely share part of a business's information or operations with suppliers, vendors, partners, customers, or other businesses. 
  • As like internet , the extranet also uses the public telecommunications system(mobile , personal computer ,laptop and so on) to share the information.
  • Extranet provides limited access to its intranet.
  • Any information that is private , not publish for everyone.


  • An extranet requires security and privacy.
  • Extranet uses the public internet as its transmission system, but requires passwords to gain entrance.
  • Extranet use the same web server technology, communication protocol and link as the internet.