Coaxial cable has been around as a technology for a long time (since the early 20th century) and has many unique advantages for reliable, accurate transmission.
It also has limitations that in some cases cause it to be replaced by fiber optic cables, category cables, or sometimes wireless signals.
The key to the success of coaxial cable is its shielding design, which allows the copper core of the cable to transmit data quickly without being disturbed or damaged by environmental factors.
The two most common cable sizes are RG-6 and RG-11:
RG stands for "Radio Rating" and they are also called RF cables, which stands for "Radio Frequency".
RG-6 cable is used for drops shorter than 150 feet.
RG-11 cable is used for longer drops due to improved performance over lengths over 150 feet.
Broadband cables used in homes have an impedance of 75 ohms.