IP Version 4 and IPv6 are both representations of binary numbers.
An IPv4 address is 32 bits and the format is decimal.
An IPv6 address is 128 bits and the format is hexadecimal.
The mask function is the same for both of these protocols. The mask represents how many of these bits in the IP address are being used to represent the network segment that is common to all the devices on that same network. The remaining host portion, or host ID, represents the individual host, such as a workstation on a specific network.
IPv4 uses classes of addresses, such as Class A, Class B, and Class C. The default mask is /8, /16, or /24, respectively, for these three classes.
IPv6 does not use the concept of classes. The traditional mask that will normally see an IPv6 address is /64, which means that half of the address is used for the network and the other half represents the host on that network.
IPv4 uses broadcasts, and MAC address resolution IPv4 uses Address Resolution Protocol (ARP).
IPv6 does not use broadcasts or ARP but instead uses multicast and the Neighbor Discovery Protocol (NDP) for resolution of MAC addresses on other IPv6 devices on the local network.