The core of the network is the most complex part of the Internet.
To the edge of the core network part of the network in providing a large number of host connectivity, so that any edge portion of a host capable (i.e., transmit or receive data in various forms) to communicate with other hosts.
Play a special role in the network core part of the router (router).
A router is a key component to achieve packet switching (packet switching), whose mission is to receive the packet forwarding, which is the core part of the network's most important functions.
The core is composed of many portions of the Internet and the network routers to interconnect them composition, and the host is in the edge portions of the Internet.
Generally use high-speed links between routers connected to the Internet core part, in the host network access edge to the core part is usually at a relatively low rate link is connected.
Hosts and routers
The user is to use the host information processing, and other hosts and may exchange information through the network.
The use of a router is used to forward the packet, i.e. packet switching.
