<human>:  What is the difference between an IPv4 and an IPv6 address?
<bot>: The main difference between an IPv4 and an IPv6 address is the amount of address space available. An IPv4 address is 32-bits long and can provide a maximum of 4,294,967,296 addressable devices. An IPv6 address is 128-bits long and can accommodate a maximum of 3.4 x 10^38 possible addresses. IPv6 also has more advanced features such as stateful addressing, improved functionality and simplification of address auto-configuration, making it much more efficient than IPv4.