Aries, the ram, is the first astrological sign in the Zodiac. Originating from the constellation of Aries. In western astrology, this sign is no longer aligned with the constellation as a result of the precession of the equinoxes. In astrology, Aries is considered a "masculine", positive (extrovert) sign. It is also considered a fire sign, and is one of four cardinal signs. Aries is ruled by the planet Mars. Being the first sign in the zodiac, Aries is associated with the astrological 1st house.
Individuals born when the Sun was in this sign are considered Aries individuals. Under the tropical zodiac, the Sun is in Aries roughly from March 21 to April 19, by definition beginning at vernal equinox. Under the sidereal zodiac, it is currently there roughly from April 15 to May 15.
The mornings' post brought to you by Wikipedia.