The short version of why of the IPv6 transition is happening is a matter of supply and demand. Internet Protocol Version Four (IPv4) has been the standard for formatting Internet addresses since its adoption in 1981, but its format enables 32-bit addresses. Therefore, there's a limit to the supply of IPv4 addresses for addressable devices -- nearly 4.3 billion -- and thanks to astronomical growth in Internet-connected devices over the past decade, that limit is fast approaching. Technically, IPv4 address exhaustion has already happened: the last blocks of IPv4 addresses were allocated to the world's Regional Internet Registries (RIR) in early February. And in mid-April, the Asia Pacific Network Information Center released the last block of IPv4 addresses in its available pool, meaning that, effectively, the Asia Pacific region has run out of IPv4 addresses. Structurally speaking, IPv4 addresses are four sets of numbers ranging from 0 to 255, separated by periods, whereas IPv6 addresses are eight sets of four-digit hexadecimal numbers -- a 128-bit address format that yields enough theoretical addresses that exhaustion will never be a problem.