Coax Cable

"Dielectric" is a 19th-century term coined by polymath William Whewell in the 1830s at the request of Michael Faraday. It derives from the Greek prefix dia- ("through") and electric describing insulating materials that allow electric field lines (flux) to pass through them while resisting electrical conduction.

Read more on how the coax signal travels (source to destination). It uses an AC wave powering the active equipment (amplifiers/nodes) along the line to the street tap, zero volts (only radio frequency RF data signals) from street tap to wall socket & Arris modem, finally a low 12v DC power at the Arris modem inside.

Compare with early Phones, having a single line with ground return, read more re early phone exchanges in Australia.