IPv6 - Definition from the Hotspot Shield Glossary
Internet Protocol Version 6 is a specification created by the IETF (Internet Engineering Task Force) to be an upgrade to the limited IPv4.
In essence IPv6 is used to generate unique IP addresses for individual devices to allow them to be identified when transferring data over any kind of network. It works in the same way as IPv4 but has added functionality and should be able to support a much greater number of devices on the internet. Where IPv4 creates IP addresses with 32 bits, IPv6 uses 128 bits which increases the total number of IP addresses that can be generated. Aside from the increased number of IP addresses, IPv6 also improves upon the routing and security features of IPv4. For the immediate future, IPv4 and IPv6 will work side by side.