Collaborative computing/Network & internetwork (internet)

Network and internetwork:

Internetwork is a network of networks that consists of many underlying physical technologies, connected by routers. A network is a collection of computers or others types of hardware, which is connected by communication channels that allow sharing of resources and information.

A collection of interconnected networks is called an internetwork or internet. These terms will be used in a generic sense, in contrast to the worldwide Internet (which is one specific internet), which we will always capitalize. The Internet uses ISP networks to connect enterprise networks, home networks, and many other networks. We will look at the Internet in great detail later in this book (Tanenbaum, 2000, 28)

A network is formed by the combination of a subnet and its hosts. ‘‘Network’’ is often used in a loose sense as well. An inter- network might also be described as a network, as in the case of WAN.

Connecting a LAN and a WAN or connecting two LANs is the usual way to form an internetwork, but there is little agreement in the industry over terminology in this area. There are two rules of thumb that are useful. First, if different organizations have paid to construct different parts of the network and each maintains its part, we have an internetwork rather than a single network. Second, if the underlying technology is different in different parts (e.g., broadcast versus point-to-point and wired versus wireless), we probably have an internetwork (Tanenbaum, 2000, 28).

There are many different types of networks for example:
 * PAN (personal area network) a local network that consist of a simple protocol, for example a pacemaker.
 * WAN (Wide area network) that covers a great geographic area, for example a country or a continent.
 * VPN (Virtual private Network)