Telefono

Teléfono is a device and system that enables two-way voice communication over distance. The word derives from Greek tele- ('far') and -phone ('sound'). In practice, the term encompasses both the hardware and the network technologies used to transmit speech and other data between callers.

The modern telephone emerged in the late 19th century, with Alexander Graham Bell receiving the first widely recognized patent for the electric telephone in 1876. Earlier claims attribute significant work to Antonio Meucci, who developed an early device called telettrofono in the 1850s. The subsequent development of telephone networks and switching systems allowed calls to be connected between distant subscribers, forming the basis for the public switched telephone network (PSTN).

Technically, early telephones converted sound into electrical signals transmitted over wired circuits. Contemporary systems use digital transmission, signaling protocols, and a range of access technologies. Fixed-line phones rely on copper or fiber networks to a central office, while mobile phones operate over wireless radio networks (2G–5G) with roaming, data services, and voice-over-IP capabilities increasingly common in hybrid networks. Satellite telephones provide coverage in remote areas, using satellites to relay signals.

Types of telecommunication devices have expanded from landlines and cordless phones to mobile and smartphones, which integrate computing, cameras, and Internet access. Telephony now intersects with messaging, video calling, and voice over IP, often delivered over data connections in addition to traditional circuits.

Impact and regulation vary by country, but telephony remains central to personal, business, and emergency communications, with considerations including privacy, number portability, and universal service obligations.