A cell phone is a portable telephone that connects to a network of cellular towers instead of being plugged into a wall. The name comes from how the system works: a region is divided into areas called cells, each covered by its own radio tower. As you move around with your phone, it automatically switches from one cell tower to another, keeping your call or internet connection going.

Cell phones revolutionized communication by letting people make calls from anywhere, not just from home or an office. The first cell phones in the 1980s were heavy, expensive devices that could only make calls. Modern cell phones, often called smartphones, are powerful pocket computers that can access the internet, take photos, play games, and run thousands of different apps.

The technology keeps evolving rapidly. What people call a cell phone today barely resembles the brick-sized devices from forty years ago. Some people still use the older term mobile phone or just mobile to mean the same thing. In everyday conversation, people usually just say phone, since cell phones have become so common that landlines (phones connected by wires) are increasingly rare.