Mars is the planet that orbits between Earth and Jupiter in the modern heliocentric order.
From the Sun outward, the planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Mars therefore follows Earth and precedes Jupiter. This arrangement is based on average orbital distance from the Sun, not on how the planets may appear lined up from Earth at a particular moment.
Mars is often called the Red Planet because iron minerals in its surface dust oxidize, or rust, giving it a reddish appearance. It is a terrestrial planet like Mercury, Venus, and Earth, with a rocky surface and a thin atmosphere. Jupiter, by contrast, is a much larger gas giant beyond Mars.
A common mix-up comes from confusing the inner-planet sequence with apparent positions in the night sky. Venus and Mercury are closer to the Sun than Earth, while Saturn lies beyond Jupiter. Mars also marks the outer edge of the Solar System’s four rocky inner planets.