Broadcast domain

• Broadcast domain

A broadcast domain is a logical division of a computer network, in which all nodes can reach each other by broadcast at the data link layer. A broadcast domain can be within the same LAN segment or it can be bridged to other LAN segments.
Any computer connected to the same Ethernet repeater or switch is a member of the same broadcast domain.
Further, any computer connected to the same set of inter-connected switches/repeaters is a member of the same broadcast domain
Routers and other higher-layer devices form boundaries between broadcast domains.
broadcast domains are only divided by layer 3 network devices such as routers or layer 3 switches
https://en.wikipedia.org/wiki/Broadcast_domain