Because broadcasting depends on the specific data link layer in use on a local network, we must discuss it with reference to both physical networks and logical networks.
The terms we will use in referring to physical networks are, from the point of view of the host sending or forwarding a broadcast:
Local Hardware Network
The physical link to which the host is attached.
Remote Hardware Network
A physical network which is separated from the host by at least one gateway.
Collection of Hardware Networks
A set of hardware networks (transitively) connected by gateways.
The IP world includes several kinds of logical network. To avoid ambiguity, we will use the following terms:
The DARPA Internet collection of IP networks.
One or a collection of several hardware networks that have one specific IP network number.