Layer 1: Physical Layer
This layer deals with the physical plugs and sockets and electrical specification of signals.
This is the medium over which the digital signals are transmitted. It can be twisted pair, coaxial cable, optical fiber, wireless, or other transmission media.
Read more about this topic: OSI Protocols
Famous quotes containing the words layer and/or physical:
“After a few months’ acquaintance with European “coffee,” one’s mind weakens, and his faith with it, and he begins to wonder if the rich beverage of home, with its clotted layer of yellow cream on top of it, is not a mere dream after all, and a thing which never existed.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)
“Philosophical questions are not by their nature insoluble. They are, indeed, radically different from scientific questions, because they concern the implications and other interrelations of ideas, not the order of physical events; their answers are interpretations instead of factual reports, and their function is to increase not our knowledge of nature, but our understanding of what we know.”
—Susanne K. Langer (1895–1985)