Everyone has a smartphone, or so it seems. In fact, there were an estimated 1.4 billion smartphones in the world as of December 2013 [source: Koetsier]. People are constantly talking on them, taking pictures, surfing the Internet and doing dozens of other things, including shopping for cars. Captain Kirk would be jealous.
At their core, smartphones, and all cell phones for that matter, are mini radios, sending and receiving radio signals. Cell phone networks are divided into specific areas called cells. Each cell has an antenna that receives cell phone signals. The antenna transmits signals just like a radio station, and your phone picks up those signals just as a radio does.
Smartphones use cell phone network technology to send and receive data (think phone calls, Web browsing, file transfers). Developers classify this technology into generations. Do you remember the first generation? It included analog cell phone technology. However, as cell phone technology progressed, the protocols became more advanced. In 2014, cell phones are in the world of the fourth generation, or 4G. Although most carriers are expanding their 4G technology, some companies, such as Samsung, are developing 5G technology, which if recent tests are any indication, will allow you to download an entire movie in less than a second. You can read more about network technologies and protocols in the article How Cell Phones Work.