Broadcast refers to a protocol that only outputs packets in a single direction usually from the master or server. Broadcast messages are useful for delivering a message to most or every device on the network.
Dynamic Host Configuration Protocol (DHCP) is one example of the protocol using broadcast messages.
A DHCP server can assign IP addresses to almost all devices on the network without having to wait for a response back. By broadcasting the allocated IP addresses to these devices the administrator or technicians of the network will not have to manually allocate and track usable IP addresses for each device.