Although objectively the Earth moves around the Sun in an elliptical orbit, we on Earth subjectively see the Sun appears to move around the Earth. The path of this motion is called the Ecliptic. The movement of the planets used in Jyotish is confined to a band of heavens that extends approximately eight degrees to both the north and the south of the ecliptic, as seen from Earth.
Although there is only one ecliptic and hence only one Zodiac, the latter is given two different names to differentiate between the two ways of measuring along the same circle. They are “Tropical zodiac and Sidereal zodiac“. Each circle of these zodiacs contains 360 degrees and each is divided by astrologers into 12 equal segments of 30 degrees each. The 12 divisions of the tropical zodiac are called signs, and the 12 divisions of the sidereal zodiac are called constellations.