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)
“I have often been reproached with the aridity of my genius; a deficiency of imagination has been imputed to me as a crime; and the Pyrrhonism of my opinions has at all times rendered me notorious. Indeed, a strong relish for physical philosophy has, I fear, tinctured my mind with a very common error of this age—I mean the habit of referring occurrences, even the least susceptible of such reference, to the principles of that science.”
—Edgar Allan Poe (1809–1849)