Solar System
The overall structure of the charted regions of the Solar System consists of the Sun, four relatively small inner planets surrounded by a belt of mostly rocky asteroids, and four giant planets surrounded by the Kuiper belt of mostly icy objects. Astronomers sometimes informally divide this structure into separate regions. The inner Solar System includes the four terrestrial planets and the asteroid belt. The outer Solar System is beyond the asteroids, including the four giant planets. Since the discovery of the Kuiper belt, the outermost parts of the Solar System are considered a distinct region consisting of the objects beyond Neptune.
Heliosphere
The solar wind consists of particles (ionized atoms from the solar corona) and fields like the magnetic field that are produced from the Sun and stream out into space. Because the Sun rotates once approximately every 25 days, the magnetic field transported by the solar wind gets wrapped into a spiral. The Solar wind affects many other systems in the Solar System; for example, variations in the Sun's own magnetic field are carried outward by the solar wind, producing geomagnetic storms in the Earth's magnetosphere.