The largest, and possibly most important, object in the solar system is the Sun. An immense fusion reactor, it is the center of the solar system both gravitationally and in terms of power, which it radiates as light.
Mercury, closest to the sun, is small and airless, pocked by craters. At a glance, it is difficult to tell Mercury apart from the Moon. Mercury has the greatest extremes of temperature of any planets.
Next outwards is Venus, a planet with strong similarities to Earth. Both planets have a similar mass and composition, however, the proximity of Venus to the Sun has caused a runaway greenhouse effect. Enormously high temperatures combined with an atmosphere with large quantities of sulfuric acid make this anet, with extremely high daytime temperatures and extremely cold night temperatures on the dark side. planet totally uninhabitable.
The third planet, Earth, is the only pmanet of our system that we know it is habitable, there are living things on this planet, we will see later the difference between this planet and the others.
Further yet is Mars. After the Moon, this is the most explored body in the solar system, and the most likely target for a future manned mission. It is called the red planet. It is smaller than Earth but it is bigger than Mercury.
The asteroid belt is usually listed next, and I will adhere to tradition. However, it is very important to note that while a great many of the asteroids are neatly orbiting where they are drawn between Mars and Jupiter, a great many are elsewhere in the solar system, those inside Earth's orbit, those that cross it, the entire stretch between Mars and Jupiter, and many more out beyond.In fact, the most important ones, both in terms of possible resources and in danger to Earth, are the 2000 or so that periodically cross our orbit.
It is possible that the asteroides were two planets which have stoken themselves.
Jupiter, named rightly for the greatest of the Roman gods, is very close to the dividing line between planets and stars. Many, many times larger than the Earth (and containing more mass than all of the other planets, moons, etc except for the sun). It is the biggest planet of our solar system.
Saturn, the second largest planet, follows Jupiter. Known mostly for its vast system of rings, it also holds the title for the most moons, 22.
Uranus is the next planet, followed by Neptune. Both are farther out than can be readily studied from Earth, and have each only received one fly-by, in both cases by Voyager 2.
Currently farthest out of the planets, Pluto is the strangest. Tiny by planetary standards, it is the farthest planet out for most of its 248-year orbit of the sun.
The telluric planets are the planets whiwch are the closest to the Sun : during the construction of the solar system, the planets which had the most important volumique masses were more attracted by the sun, and the gaseous planets were furthest from the sun because their volumique masses were less important. Pluto is probably an other telluric planet, if it is one, it is possible that Pluto came from an other solar system.
Beyond Pluto is the Kuiper Belt, made up of comets and small planet-like bodies very similar to Pluto. Once again, like Pluto, these objects are too small and too far away to really study.