Learn in the textbookIP Addresses and the Address System
DefinitionIPv6 is the IP version created to end the IPv4 address shortage, and it extends the address length to 128 bits (128ビット).
ExplanationIt can express 2 to the 128th power addresses, a scale at which running out is no practical concern. The notation is hexadecimal in 16-bit groups separated by colons, so even when letters appear it is still a numeric value, not a name like a domain name.
AnalogyThink of making a membership number much longer. Each added digit multiplies the total supply of numbers.