What is the difference of inner planets and outer planets?

The inner planets are rocky, and do not have any rings. They are all fairly small, with our planet, Earth, being the largest, then Venus, then Mars, then Mercury. Most of them have moons, and none have rings. The outer planets are made of gas, and are huge compared to the inner planets. Every single one of these outer planets have moons and rings. Jupiter is the largest, followed by Saturn, Uranus and Neptune.