It's hard to imagine life without phones. From the earliest electric telegraph to today's powerful technology, phones have played a huge role in history. The invention of phones changed how the world communicates. This book provides readers with a before-and-after look at the way the world has changed. Each book in the NGSS-aligned It Changed the World series introduces readers to some amazing inventions. Interesting facts and vivid photos show how these inventions changed, and continue to change, the lives of people around the world. Each book includes a glossary, comprehension questions, and an extension activity for further learning.