What does it mean to be ruled by Jupiter?

Jupiter governs long distance and foreign travel, big business and wealth, higher education, religion, and the law. It is also associated with the urge for freedom and exploration, as well with gambling and merrymaking.

What signs are rules by Jupiter?

Rulerships of signs

House Sign Domicile Ruling body (modern)
7th Libra Venus
8th Scorpio Pluto
9th Sagittarius Jupiter
10th Capricorn Saturn