In an Ethernet network, broadcast traffic is sent to all devices within the network segment. This means every device receives and processes the broadcast packets, which can lead to high network load and congestion, making it inefficient for applications like network video where large amounts of data need to be transmitted reliably and efficiently. Axis documentation advises against relying on broadcast traffic for video streams, as it can degrade network performance and the quality of the video feed due to the excessive load on the network.