What two groups are the planets of the solar system divided into?

At the moment, astronomers are generally considered to have eight planets in our solar system (there used to be nine, but Pluto is no longer considered a planet). They are divided into two main groups in structure: solid (terrestrial planets) and gas planets. Each group includes four planets. The solid planets, which include our Earth, are many times smaller than the gas giants. And the largest planet is Jupiter.