The Sun is the most powerful body in Astrology's sky. It influences the way we express ourselves, our overall energies and our broad personalities. While you have many signs -- every planet in our solar system was in one of the 12 zodiac signs when you were born -- your Sun sign is what's generally referred to as "your zodiac sign" -- as in, "Hey Baby, what's your sign?"
In Astronomy, the Sun is the center of our solar system and all the planets orbit around it. Astrology, however, is Earth-centric, meaning it's based on our perspective of the planets, and their relationship to each other, from here on Earth. So when the Sun shifts from one zodiac sign to the next, it's not the Sun that is physically moving, but our viewpoint of it -- and therefore, our connection to and relationship with its energies -- from Earth.
Zodiac sign the Sun rules: Leo
Exalted in: Aries
House the Sun rules: 5th House of Expression and Play
The Sun retrogrades: never
The Sun stays in each zodiac sign for: one month
The Sun makes a complete trip through the zodiac: once every year
In Roman mythology, the Sun is associated with Apollo (or in Greek mythology, Helios), the God of Light or the Sun God.