IP address classification

Any - any, cast - throw

Anycast - routing technology, provides sending a packet to the "first available" group in anycast. Those. Whoever first received the package is processing it. The remaining members of the Anycast group will not see this package.

If in simple terms, the same IP address is assigned to several servers located in different places and when a request is made to the address, the closest one is selected (the smaller the passage points of the packet, the closer)

In more detail in article with Habrahabr:

The meaning of the Anycast method is to announce the same IP address prefix from several network points simultaneously via BGP. As a result, the data is transmitted along the shortest route - to the closest node to which the announced IP address is assigned. In this case, the concept of “short route” in this case is interpreted not in a geographical, but in a topological sense.