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:
“This world is run by people who know how to do things. They know how things work. They are equipped. Up there, there’s a layer of people who run everything. But we—we’re just peasants. We don’t understand what’s going on, and we can’t do anything.”
—Doris Lessing (b. 1919)
“Whenever reality reinforces a child’s fantasied dangers, the child will have more difficulty in overcoming them...So, while parents may not regard a spanking as a physical attack or an assault on a child’s body, the child may regard it as such, and experience it as a confirmation of his fears that grown-ups under certain circumstances can really hurt you.”
—Selma H. Fraiberg (20th century)