What is the difference between Internet, ethernet, intranet and extranet?

Difference between internet Internet intranet extranet ?

• what is the difference among internet, Internet, intranet, and extranet ??

• Answer:

  I want to give some explanations about the difference of internet and extranet so the definition of internet is; Internet: “A global computer network providing a variety of information and communication facilities, consisting of interconnected networks using standardized communication protocols.” Extranet: “An extranet is a private network that uses Internet technology and the public telecommunication system to securely share part of a business's information or operations with suppliers, vendors, partners, customers, or other businesses.” The details of internet is “The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite (TCP/IP) to serve several billion users worldwide. It is an network of networks that consists of millions of private, public, academic, business, and government networks, of local to global scope, that are linked by a broad array of electronic, wireless and optical networking technologies. An extranet requires security and privacy. These can include firewall server management, the issuance and use of digital certificates or similar means of user authentication, encryption of messages, and the use of virtual private networks (VPNs) that tunnel through the public network.