List and describe three improvements that IPv6 has over IPv4.

What will be an ideal response?

Larger address space-IPv4 addresses are 32 bits, which provide a theoretical four billion addresses. IPv6 addresses are 128 bits, so the number of possible addresses can be expressed as 34 followed by 37 0s, or 340 trillion trillion trillion.
Hierarchical address space-Unlike IPv4, in which numbers in the address have little meaning other than the address class, and the network ID and host ID, IPv6 addresses have a more defined structure.
Autoconfiguration-IPv6 can be self-configuring or autoconfigured from a router or server running IPv6 or through DHCPv6.
Built-in quality of service (QoS) support-IPv6 includes built-in fields in packet headers to support QoS strategies.
Built-in support for security-From the ground up, IPv6 is built to support secure protocols, such as Internet Protocol Security (IPsec).
Support for mobility-With built-in support for mobility, routing IPv6 packets generated by mobile devices over the Internet is more efficient than with IPv4.
Extensibility-IPv6 uses extension headers instead of IPv4's fixed-size 40-byte header.