Data-link layer
Layer 3
A device that opens and closes a circuit is called a switch.
Physical layer
Function controller
No, a lava lamp is not considered a type of optical device.
its a switch
The kind of telephone switch type at the ATT Phillips Tel 5ESS-PBX host is a step by step tone. This is the standard switch type used by ATT and most large telephone companies.
Toggle = back and forth, or on and off. A toggle switch toggles (turns) a light or other device on or off. Good example is a light switch (the wall kind)-- a toggle switch must also be of the "throw the stick back and forth" kind. Which a light switch basically is.
A puff and suck switch is a device that a person wears where a tube goes into the mouth, and then they can puff and suck to select different things. It's like a kind of mouse for the computer except you operate it with your mouth.
computer is a electronic device
A storage device.
This kind of a hard disk device is the most commontly use in office.