Telecommunications, also known as telecom, is the exchange of information over significant distances by electronic means and refers to all types of voice, data, and video transmission. This is a broad term that includes a wide range of information transmitting technologies such as telephones (wired and wireless), microwave communications, fiber optics, satellites, radio and television broadcasting, the internet and telegraphs. 

A complete, single telecommunications circuit consists of two stations, each equipped with a transmitter and a receiver. The transmitter and receiver at any station may be combined into a single device called a transceiver. The medium of signal transmission can be via electrical wire or cable (also known as “copper”), optical fiber, electromagnetic fields or light. The free space transmission and reception of data by means of electromagnetic fields are called wireless communications.

Telecommunications service providers

Telecommunications systems are generally run by telecommunications service providers, also known as communications service providers. These providers historically offered telephone and related services and now offer a variety of internet and WAN services, as well as metropolitan area network and global services.

 In many countries, telecom service providers were primarily government owned and operated, but that is no longer the case, and many have been privatized. The International Telecommunication Union is the United Nations agency that administers telecommunications and broadcasting regulations, although most countries also have their own government agencies to set and enforce telecommunications guidelines. In the United States, the Federal Communications Commission is the primary regulatory agency.

 Within the large umbrella of companies that provide different types of telecommunications services are internet service providers, wireless service providers, radio and television broadcasters, cable companies, satellite television providers and managed service providers.

The word telecommunications comes from the Greek prefix tele, which means distant, combined with the Latin word communicare, which means to share.