Telecommunications, often referred to as telecom, encompasses the exchange of information over long distances through electronic means. This broad term includes a variety of voice, data, and video transmission methods. Telecom technology covers a wide array of communication infrastructures, including wired phones, mobile devices, microwave communications, fiber optics, satellites, radio and television broadcasting, the internet, and telegraphs.

A complete telecommunications circuit typically involves two stations, each equipped with a transmitter and a receiver, which can be combined into a single device known as a transceiver. Signal transmission may occur via electrical wire (copper), optical fiber, electromagnetic fields, or light. Wireless communications refer to the free-space transmission and reception of data using electromagnetic fields.