The following is largely paraphrased from wikipedia...
Jupiter is the fifth planet from the Sun and the largest planet
within the Solar System; it is visible to the naked eye in the
night sky and can occasionally be seen in the daytime when the sun
is low. The average distance between Jupiter and the Sun is 778
million km (about 5.2 times the average distance from the Earth to
the Sun) and it completes an orbit every 11.86 years. Jupiter's
rotation is the fastest of all the Solar System's planets,
completing a rotation on its axis in slightly less than ten
hours.
Jupiter has 64 named natural satellites. Of these, 47 are less
than 10 kilometres in diameter and have only been discovered since
1975. The four largest moons, known as the "Galilean moons," are
Io, Europa, Ganymede and Callisto.
The planet was known by astronomers of ancient times and was
associated with the mythology and religious beliefs of many
cultures. To the Babylonians, this object represented their god
Marduk. In ancient Roman religion and myth, Jupiter is the king of
the gods and the god of sky and thunder. He is the equivalent of
Zeus in the Greek pantheon.
In the Greek-influenced tradition, Jupiter was the brother of
Neptune and Pluto. Each presided over one of the three realms of
the universe: sky, sea, and the underworld. Jupiter remained Rome's
chief official deity throughout the Republican and Imperial eras,
until displaced by the religious hegemony of Christianity.