Final answer:
The broadcast address for an IPv4 network occurs when all host bits are set to 1, which allows data to be sent to all hosts on a local network.
Step-by-step explanation:
The broadcast address on an IPv4 network is defined as the address where all host bits are set to 1. This address is used to send data to all hosts within a local network segment.
The broadcast address can be calculated based on the network address and the subnet mask. However, it is not simply when the final octet is 255, as this could be a valid host address in larger subnets. The broadcast address is also not router defined or arbitrary; it strictly depends on the IP addressing scheme in use.