A circuit is the path over which information is transmitted through devices such as routers, switches, and other network devices. In circuit-switching, the path is decided before the transmission of data begins using a resource-optimizing algorithm. Packets are a whole piece of data transmitted in chunks and includes information about the IP address of the source and destination network devices,
. sequence numbers and other vital information. Packet-switching requires each packet to find a route to the next destination on its own, deciding where to go next once it reaches it until reaching the final IP destination. Learn more about packet and circuit switching at http://voip.about.com/od/voipbasics/a/switchingtypes.htm.
