Every device connected to the internet needs an IP address. The original standard, IPv4, only allowed for about 4.3 billion addresses. We ran out of those completely years ago.
The NAT workaround
The internet didn’t break because engineers heavily relied on Network Address Translation (NAT)—a system where one public IP address is shared by dozens of private devices.
The sheer scale of IPv6
The new standard, IPv6, uses a 128-bit address space. It provides enough unique addresses to assign one to every atom on the surface of the Earth, eliminating the need for NAT.
The silent upgrade
Major ISPs have been quietly transitioning their backbones. Over 40% of global traffic now runs on IPv6. It is one of the largest infrastructure upgrades in history, executed silently.