If you have two separate networks, you may need a way to pass data from one network to the other. This is commonly done by connecting the two subnets with a router, hub, or switch.
A Linux system can be used for a network bridge.
A bridge is a low-level connection that passes packets based on their MAC address instead of being identified by the IP address. As such it requires fewer machine resources and is more efficient.
You can use a bridge to link virtual machines on private, non-routed networks, or to link separate subnets in a company, for instance, to link a manufacturing subnet to the shipping sub-net so production information can be shared.
