Communication channels carry data from one computer to another.
Physical connections are between sending and receiving devices.
-pair cable are set of copper wires twisted together. Coaxial is a single copper cord. Fiber optic cable transmits as pulses of light through tiny tubes of glass. Wireless communications do not use a substance to connect, just air. Bluetooth is short range radio communication standard. Wi-Fi is wireless fidelity communicates over short distances. A microwave uses high frequency radio waves. WiMax allows greater distances for Wi-Fi. LTE promises greater speed and frequency in the near future. Satellite uses satellites orbiting about 22,000 miles above earth. Infrared are light waves used in a short distance.