talk about inventions smartphone their uses and benefit (ko sao chép mạng ) cảm ơn nhiều ạ

The telephone is a telecommunications device that is used to exchange information, most commonly, voice - speaking, " voice ", between two or more people. Phones speak voice to electrical signals and transmit in complex telephone networks through connection to other users. Such a performance system has two basic components: 
Terminal equipment, commonly called the " ", " name, is called the " nói " name to transmit, and convert the signal signal to the sound. 
Telephone networks connect and transmit, connect users related to each other and transmit signals. 
The development of technology leads to today' s network of more energy, like fax, internet,... And next to traditional wires, there are new ways of transmitting.