METU, who has been actively working leadingly in the deployment of ipv6 in Turkey, is going to participate in "World IPV6 Day" activities. In scope of studies that take palce in http://worldipv6day.org/, METU is going to give ipv6 support to its web pages for a day.

Every device that connects to the Internet needs an address. But those addresses are rapidly being depleted. A critical point in the history of the Internet was reached today with the allocation of the last remaining IPv4 Internet addresses from a central pool. Internet Specialists foresaw the problem and back in 1996, devised a solution that would provide 340 trillion trillion trillion separate addresses, called IPv6.

Adoption of that solution has been slow. Since it is not directly
compatible with the current IPv4 system, there is inertia to the move.
However, the benefits of IPv6 are long-term. It means the future
expansion of the Internet is now dependent on the successful global
deployment of the next generation of Internet protocol.

IPv6 was started for the lack of IPv4 number and mostly used by the countries that do not have enough of IPv4, china, korea, japan etc.
The number of IPv6 is 2¹²⁸. This makes 340282366920938463463374607431768211456 IP addresses. This is a really huge number.

The notation of IPv6 is different than IPv4. IPv4 is parted by 8-bit (dot) notation. However, IPv6 is parted with colon by 16-bit notation. Eg.
2001:0098:0A11:0010:0011:0000:0000:0106.
Also for the simplicty the leading 0s had been canceled, 2001:A98:A11:10:11:0:0:106. At last, fields that consists of 0s has been summerized as 2001:A98:A11:10:11::106.
As you can see :: symbol used for :0000:0000: , this makes IPv6 number more readable. But do not forget that the last notation can be use only one time. Therefore, 2001:A98::10::106 is strictly wrong. As you can understand that it is not clear this IPv6 address shows!

Loopback address:

::1 --> 0:0:0:0:0:0:0:1

As you may notice, there are 8 fields that consists of 16-bit HEXadecimal numbers.