In our solar system, nine planets circle around our Sun. The Sun sits in the middle while the planets travel in circular paths (called orbits) around it. These nine planets travel in the same direction (counter- clockwise looking down from the Sun's north pole).
The picture below shows the different paths and positions of each planet.
The inner solar system contains Mercury, Venus, Earth and Mars. These four planets are closest to the Sun.
The inner planets are separated from the outer planets by the Asteroid Belt.