Jargon in any industry generally develops as a time-saving protocol that allows industry participants to communicate more quickly, effectively and accurately. Understanding the jargon of telecommunications can help you better understand how your own system works. The basic building blocks of any telecommunications network are called links.
Links are simply transmission media through which messages travel.
Physical links include the trunks and cables people often refer to as telephone lines. Common configurations are twisted wire pairs, which are made of copper and coaxial cables, which are also made of copper and contain many wires in one trunk. Fiber optics are made from glass. Unlike copper links, which transmit messages in the form of electrical impulses, fiber optics transmit messages in the form of light and at the speed of light. Information transmitted over a fiber optic cable can be sent more cheaply, efficiently and purely than the same information sent over a copper cable.