IPv4
IPv4 addresses contain 32 bits and are normally written as four decimal numbers, for example 192.0.2.1. The limited address space led to widespread use of network address translation.
IPv6
IPv6 uses 128-bit addresses written in hexadecimal groups. Its enormous address space supports modern growth and reduces dependence on address sharing.
Can both work together?
Yes. Many networks use dual stack, allowing devices to communicate over either IPv4 or IPv6 depending on destination support and routing.
Is IPv6 more private?
Not automatically. Modern operating systems use temporary privacy addresses, but privacy still depends on network configuration, browser behavior, accounts and cookies.