Depending on a destination network device's mac address, which network device receives data from a source network device and distributes it to that device?

A single LAN connection links two hundred workstations and four servers, which are in turn linked to one another through a network of switches. You seem to be getting a large number of broadcast packets across your LAN, and you would want to lessen the load that this traffic is placing on your network. Specifically, what actions must you take to accomplish this?

Which device transmits data from the source network device to the target network device based on its mac address?

It is possible to share a MAC address across two network interfaces, but how? Do you know why this is the case? Using the same IP address on two different network interfaces is technically possible. Do you have any thoughts on why this is happening?