Zodiac is a basic concept in astrology, which describes the ring of zodiac constellations, that lines the ecliptic, which is the apparent annual path of the Sun across the sky. Vernal equinox is the beginning and the end of the zodiac.
The zodiac consists of twelve 30°-sectors of celestial longitude, which correspond to the twelve zodiac constellations (zodiac signs): ♈ Aries, ♉ Taurus, ♊ Gemini, ♋ Cancer, ♌ Leo, ♍ Virgo, ♎ Libra, ♏ Scorpio, ♐ Sagittarius, ♑ Capricorn, ♒ Aquarius and ♓ Pisces.
Zodiac signs are ruled by a planet. The traditional rulerships are the well known to the ancient people Lights and planets. Sun rules Leo, Moon rules Cancer, Mars rules Aries and Scorpio, Venus rules Taurus and Libra, Mercury rules Gemini and Virgo, Jupiter rules Sagittarius and Pisces, Saturn rules Capricorn and Aquarius.
The twelve zodiac signs are grouped into the four elements Triplicity. The two positive, self-expressive: Fire and Air, and the two negative, self-containing: Earth and Water. Fire is the element of Aries, Leo and Sagittarius. Air is the element of Gemini, Libra and Aquarius. Earth is the element of Taurus, Virgo and Capricorn. Water is the element of Cancer, Scorpio and Pisces.
Each of the four elements take part with a zodiac sign within every of the three modalities (qualities) Quadruplicity: Cardinal (Aries, Cancer, Libra, Capricorn), Fixed (Taurus, Leo, Scorpio and Aquarius) and Mutable (Gemini, Virgo, Sagittarius, Pisces).
Fire and Air zodiac signs are positive. They are masculine, diurnal (day-oriented), dry, active and extroverted. Water and Earth zodiac signs are negative. They are feminine, nocturnal (night-oriented), sensitive, moisture and introverted.
The tropical zodiac begins with the masculine Aries, then zodiac signs consecutively alternate in gender till the end of zodiac with feminine Pisces.
Celestial body passing trough a masculine sign brings spirituality and physical or mental activity, while passing trough a feminine sign of the zodiac, it makes sensitive and emotional influence.
Earth seasons can be aligned to elements of the zodiac too. Spring links to air, summer to fire, autumn to earth and winter to water. Not to be confused with the season, when the Sun is in the zodiac constellations.
Some modern astrologers consider the newly discovered planets as rulers or co-rulers of certain signs. Other take into account thirteenth zodiac sign - ⛎ Ophiuchus (the serpent bearer), because boundaries of its constellation lie on the Sun's annual path too - after Scorpio and before Sagittarius.