Telephone

A telephone is a kind of telecommunications device that allows two or more people to communicate when they are too far away to be heard directly by one another. Sound, normally and most efficiently the human voice, is converted by a telephone into electrical signals that are conveyed through cables and other communication channels to another telephone, which reproduces the sound for the receiving user. 'Distant voice' is derived from the Greek words tle (meaning far) and v (meaning voice), which combined imply distant voice. When referring to the phrase, a typical abbreviation is phone, which was initially used practically immediately after the first patent was granted.

Alexander Graham Bell was the first person to be issued a patent in the United States for a device that generated plainly comprehensible reproduction of the human voice at a second device, which was granted in 1876 to Bell. Many others contributed to the development of this device, which quickly became necessary in industry, government, and private houses alike.

In order for a telephone to function, it must have two key components: a microphone (transmitter) through which you may talk and an earphone (receiver) that can replicate your voice in another place. In fact, most telephones are equipped with such a ringer to alerting of an incoming telephone call as well as a dial or keypad for entering a telephone number when making a call to another telephone number. Throughout a conversation, the receiver and transmitter are often housed in a handset that is held up to the ear and mouth during the exchange. The dial may be situated on the handset or on a base unit to which the handset is attached, depending on the configuration. The transmitter turns sound waves into electrical signals, which are then sent across a telephone network to the receiving telephone, which converts the signals into audible sound in the receiver or, in certain cases, through a loudspeaker, depending on the situation. Telephones are duplex devices, which means that they are capable of transmitting in both directions at the same time.

In the beginning, telephones were directly linked to one another, connecting a customer's office or house with another customer's office or residence. Because they were unworkable for any number of consumers beyond a small number, these systems were rapidly supplanted by manually controlled centrally located switchboards. These exchanges were quickly linked together, ultimately becoming a fully automated, international public switched telephone network (public switched telephone network). Various radio technologies for transmission between mobile stations aboard ships and vehicles were developed in the mid-20th century to allow for increased mobility and portability. Hand-held mobile phones were first launched for personal use in 1973, and have been in use ever since. Over the course of many decades, their analogue cellular system was transformed into digital networks with better capabilities at a reduced cost.

The convergence of technologies has provided most current mobile phones with capabilities that go well beyond basic audio communication. The majority of them are smartphones, which integrate all mobile communication and many computer requirements.