Since IPv4 was running out of available computer addresses, IPv6 was introduced. IPv4 employs 32-bits of digits, so there is a maximum of 4.3 billion possible addresses. While this seems like a large amount, every computer, printer, PlayStation, and even soda machines require a unique address;. There aren’t enough bits in IPv4 to accommodate them all.
IPv6 (Internet Protocol Version 6), uses 128-bits which gives it a trillion-trillion-trillion, also called an undecillion (3.4 X 10^38 possible addresses); This is such an absurdly large number that we should have plenty of available IPv6 addresses far into the future. This change from IPv4 to IPv6 remains largely unseen by the public as the devices we buy already include the upgrade.
IPv6 addresses use 8 sets of 4 hexadecimal addresses separated by a (:) colon. There are 16-bits in each set. A good example of an IPv6 Address would be fe80::2000:aff:fea7:f7c. The /64 bit on the end is from the IPv4 days and is called CIDR (Classless Inter-Domain Routing). The CIDR splits the address into 2 parts. The first half is used as an address for the network and the second part as an address for the device. The first 3 of the 8 groups are the site prefix, the 4th group describes the topology, and the last 4 groups contain the interface ID.
Gil, Paul (2017). What is IPv4? IPv6? Why is this Important? Retrieved from https://www.lifewire.com/what-is-ipv4-ipv6-2483315. 02 May 2017.
Hardiman, Nick (2013). IPv6 Address Breakdown. Retrieved from http://active-technologies.com/content/ipv6-address-breakdown. 02 May 2017.