IPv6 was developed to address limitations in IPv4, primarily the limited available address space. IPv6 features a 128-bit address space, providing vastly more addresses than IPv4. It also has a simplified header format and built-in support for security. The document discusses the need for IPv6 due to growth of internet-connected devices. It describes IPv6 addressing formats, types of addresses, and how addresses are represented. IPv6 enables more efficient routing through larger address space and built-in mobility and security features.