The Internet is a system of interconnected devices which uses a full stack of protocols over a number of layers. In early 1960, the first packet-switched network ARPANET was introduced by the United States Department of Defense (DOD) which used a variety of protocols. Later, with the invention of TCP/IP protocols the possibilities were infinite. Many standards were evolved over time to facilitate the communication between devices over a network. Application layer protocols, routing layer protocols, access layer protocols, and physical layer protocols were designed to successfully transfer the Internet packets from the source address to the destination address. Security risks were also taken care of during this process and now we live in the world where the Internet is an essential part of our lives.
The world had progressed quite a far from ARPANET and the scientific communities had realized that the need of connecting more and more devices was inevitable. Thus came the need for more Internet addresses. Internet Protocol version 6 (IPv6) was developed to give support to an almost infinite number of devices. It uses 128 bit address, allowing 2^128 (3.4 e38) devices to successfully transmit packets over the Internet. With this powerful addressing mechanism, it was now possible to think beyond the traditional communication over the Internet. The availability of more addresses opened the way to connect more and more devices. Although, there are other limitations in expanding the number of connected devices, addressing scheme opened up significant ways.