Many of the components that make up today's Ethernet LANs were defined in the early years of the original coaxial cable Ethernet LANs. A brief tour of the design of these early LANs is a quick and painless way to introduce Ethernet LAN architecture and terminology.
The purpose of the discussion that follows is to establish some basic terminology and concepts. Many details have been omitted so that some major pieces of the framework can be nailed in place. Later chapters will tell the whole story.
Figure 3.1 shows a very simple Ethernet LAN made up of several desktop systems and a server attached to a coaxial cable.