History

• The first installation of coaxial cable occurred in England in 1936. The cable transmitted 40 phone calls between London and Birmingham. Major electronics manufacturers (Sony, Philips, etc.) first released HDMI version 1.0 in December 2002.
  
  

Types

• High-definition televisions can be connected to other theatre components using HDMI cables.black lcd silver image by Nicemonkey from Fotolia.com
  
  The two most common types of coaxial cable are 75 and 50 ohm. Video and television signals are transmitted using 75 ohm cable. Radio transmissions and data communications usually transmit over 50 ohm cable. Version number identifies the HDMI cable iteration. Each newer version has the same capabilities as the version before it with added functionality as required by the corresponding HDMI standard.
  
  

Facts

• The best-known use of coaxial cable is as a transmitter for cable television programming. HDMI connects high-definition components of a home theater system to each other, such as a Blu-ray disc player to a digital television.
  
  

Structure

• A coaxial cable consists of a center conductor, insulating dielectric layer (insulation), an outer conductor layer and a protective sheath as the last layer. HDMI cable is comprised of four shielded, twisted pairs of cable.
  
  

Function

• In a coaxial cable, the conductors and dielectric layer work together to keep the signal confined to the cable, preventing interference from nearby objects. HDMI simplifies cabling in home theater because it carries both audio and visual digital information.