What do you know about IPv6 anycast?

An Internet Protocol Version6 address (IPv6 address) is a numerical label that is used to identify a network interface of a computer or other network node participating in an IPv6 computer network.
An IP address serves the purpose of uniquely identifying an individual network interface of a host, locating it on the network, and thus permitting the routing of IP packets between hosts.
For routing, IP addresses are present in fields of the packet header where they indicate source and destination of the packet.IPv6 is the successor to the Internet's first addressing infrastructure, Internet Protocol version4 (IPv4).
In contrast to IPv4, which defined an IP address as a32-bit value, IPv6 addresses have a size of128 bits.
Therefore, IPv6 has a vastly enlarged address space compared to IPv4.

in anycast there could be2 or machines having the same IPv6  from the routinf prespective and under the RFC terms the router will pick the closest machine.
Anycast is a network addressing and routing methodology in which datagrams from a single sender are routed to the topologically nearest node in a group of potential receivers, though it may be sent to several nodes, all identified by the same destination address." Ex.
Multiple DNS servers, using the same anycast address. 
  The closest device (based on routing metrics) will be sent the DNS request packets.
 

I do not know and I want to learn it and know that accrue to the benefit system Alcet or technology in the field of Communications

An IPv6 anycast address is an address that is assigned to a set of interfaces that typically belong to different nodes.
Anycast addresses are syntactically indistinguishable from unicast addresses, because anycast addresses are allocated from the unicast address space.