AT&T is a US-based telecoms company, and the second largest provider of mobile services and the largest provider of fixed telephone services in the US.
AT&T operates as a carrier of both fixed and mobile networks in the US but also offers telecoms services elsewhere. It is the largest telecoms operator in the world by revenue. AT&T also uses its network to offer peripheral services, including disaster recovery.
AT&T can chart its origins back to Alexander Graham Bell, inventor of the telephone. The inventor’s company, Bell Telephone Company, was the parent company of subsidiary American Telephone and Telegraph Company (AT&T), established in 1885.