IPv6 (Internet Protocol (IP) version 6) is the Internet's next-generation IP intended to replace IPv4.
IP is the language that computers use to communicate with each other on the Internet. An IP address is a unique number assigned to every computer connected to the Internet. IPv4 is the protocol currently used to direct almost all Internet traffic.
The growth of the Internet created a need for more addresses than are possible with IPv4. The Internet Engineering Task Force developed IPv6 in anticipation of IPv4 address exhaustion.
In IPv4, every IP address is 32 bits long, which allows for 4.3 billion unique IP addresses. IPv4 addresses consist of four numbers separated by periods.
In comparison, IPv6 addresses are 128 bits long, which allows for approximately 3.4 x 1038 unique IP addresses. IPv6 addresses consist of eight groups of hexadecimal numbers separated by colons.
To save space, IPv6 often omits groups of numbers that contain all zeros, leaving a colon separator to mark the gap.
For more information, see IPv6 Address Notation .