Compared to the terrestrial planets, the jovian
planets are
(1) larger and less dense
(2) smaller and more dense
(3) closer to the sun and less rocky
(4) farther from the sun and more rocky

Compared to the terrestrial planets, the Jovian planets are larger
and less dense.

We can't see any solid surface of Jupiter, Saturn, Uranus, or
Neptune, and their masses suggest that if they even have any
solid body inside their deep atmospheres, it must be very small. 

Saturn in particular has a density of less than 1 gram per cm³. 
That means that if you can imagine a big enough ocean of water,
the planet Saturn would float in it !