Why are communication lines called optical cables

Communication lines are called optical cables because they transmit data using light signals through thin strands of glass or plastic, rather than electrical currents.

Optical cables, also known as fiber-optic cables, consist of a core made of ultra-pure glass or plastic through which light travels, surrounded by a cladding layer that keeps the light confined via total internal reflection . This design allows data to be transmitted as pulses of light, representing binary information, over long distances with minimal loss . The outer layers of the cable provide protection against physical damage, moisture, and environmental stress . Unlike traditional copper cables that carry electrical signals, optical cables rely on optical principles—hence the term "optical"—to guide light efficiently from the transmitter to the receiver . The use of light enables extremely high data rates, low signal attenuation, and immunity to electromagnetic interference, making optical cables ideal for modern telecommunications, internet backbones, and high-speed data networks . In practice, lasers or LEDs generate the light pulses, which travel through the fiber core, and photodetectors at the receiving end convert the light back into electrical signals for processing . This method of using light as the transmission medium is the defining feature that gives optical cables their name and distinguishes them from conventional electrical communication lines.