IP address
An Internet Protocol address (IP address) is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication.
An IP address serves two principal functions: host or network interface identification and location addressing.
IPv6 address
A 64-bit interface identifier is most commonly derived from its 48-bit MAC address. A MAC address is turned into a 64-bit EUI-64 by inserting in the middle: . When this EUI-64 is used to form an IPv6 address it is modified: the meaning of the "Universal/Local" bit (the 7th most significant bit of the EUI-64, starting from 1) is inverted, so that a 1 now means "Universal". To create an IPv6 address with the network prefix it yields the address (with the "Universal/Local" bit, the second-least-significant bit of the underlined quartet, inverted to 1 in this case because the MAC address is universally unique).