The ionosphere is a region of Earth's upper atmosphere, extending from about 30 miles (48 kilometers) to 600 miles (965 kilometers) above the surface. It contains a high concentration of ions and free electrons, which are created by solar radiation. This layer plays a crucial role in radio communication by reflecting radio waves back to Earth, allowing long-distance transmission. The ionosphere is divided into several layers, including the D layer, E layer, and F layer, each with different characteristics and functions. Its properties can change with solar activity, affecting satellite operations and global positioning systems (GPS). Understanding the ionosphere is essential for improving communication technologies.