The dots are just for human readability, showing the address byte-by-byte, and don&#x27;t have any &quot;meaning&quot; anymore. Geographic structure is also only accidental.<p>Subdivisions nowadays happen nearly everywhere and noted with a a slash and a number after the IP address (e.g. 215.54.87.0&#x2F;24 is the network containing all addresses where the first 24 bits are the same as in 215.54.87.0, 215.54.87.0&#x2F;28 would be all the addresses where the first 28 bits are the same etc).<p>The rules differ a bit between the regions, but if I remember correctly a &#x2F;24 is the smallest that can be officially assigned to an entity and announced in the global routing tables. They are free to slice smaller inside their networks though, and e.g. give a customer a &#x2F;28 or &#x2F;30 to use.<p>I hope that is somewhat understandable, I&#x27;m having a hard time putting it in words...<p>EDIT: IPv6 is same principle (although the notation for the address itself is now different). One important size there is &#x2F;64, which is the subnet size for which automatic address assignment works, and the default size for subnets containing end devices. If you get IPv6 internet, you get at least a &#x2F;64 (although a &#x2F;56 is recommended), so you don&#x27;t need NAT because you have more than enough addresses for everything.