Energy & Green Tech

Improving solar cell efficiency with a bucket of water

Looking at your cell phone, you realize the battery is low, which means you have to make another long walk into town to pay money to charge the device. By the time you get home, it's getting dark. You light the kerosene lamp ...

Consumer & Gadgets

Huawei unveils 5G phone with foldable screen

Chinese telecoms giant Huawei on Sunday unveiled a phone with a folding screen, just four days after rival Samsung became the first major handset maker to offer the feature.

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Telephone

The telephone (from the Greek: τῆλε, tēle, "far" and φωνή, phōnē, "voice") is a telecommunications device that transmits and receives sound, most commonly the human voice. It is one of the most common household appliances in the developed world, and has long been considered indispensable to business, industry and government. The word "telephone" has been adapted to many languages and is widely recognized around the world.

The device operates principally by converting sound waves into electrical signals, and electrical signals into sound waves. Such signals when conveyed through telephone networks — and often converted to electronic and/or optical signals — enable nearly every telephone user to communicate with nearly every other worldwide. Graphic symbols used to designate telephone service or phone-related information in print, signage, and other media include ℡, ☎, ☏, and ✆.

This text uses material from Wikipedia, licensed under CC BY-SA