They allow users to share peripherals, access common databases and programs and work jointly on shared files with other users. However, many businesses want to link their LANs in one location with those in another, and that's where WANs come into the picture. WANs use either a leased line or a switched connection such as ISDN or frame relay. The bridge is the simpler of the two, as it can be installed into the network right out of the box. It will learn the network configuration from the messages that are sent.
Most network managers prefer to use a router.
While more complicated to install, routers can provide crucial firewalls to enhance both network security and reliability. When LANs were used to access devices, there was no need for the network to go far. When they began to be used to access information, there was no limit on where the network needed to go.