Jovian Planets are those that consist mainly of gas and some ices.  They are quite unlike our own Earth.  The four that we know of in our planetary system all rotate more quickly than Earth.  And the interiors of these planets are totally unlike the interiors of terrestrial planets.  Below you see the four jovians, shown to the correct relative scale.  Note that they seem to come in two different colors!  Jupiter and Saturn are easy targets for even a small telescope and it is fascinating to follow their orbiting moons.   But one thing that all of the giant planets have in common is that they have ring systems of some sort. Shall we take a tour with Celestia?
Carpe Caelum Planetary Astronomy
Carpe Caelum Planetary Astronomy