Wheel of the zodiac: This 6th century mosaic pavement in a synagogue incorporates Greek-Byzantine elements, Beit Alpha, Israel.
The Earth in its orbit around the Sun causes the Sun to appear on the celestial sphere moving over the ecliptic (red), which is tilted with respect to the equator (blue-white).
In both astrology and historical astronomy, the zodiac (Greek: ζῳδιακός, zōidiakos) is a circle of twelve 30° divisions of celestial longitude that are centered upon the ecliptic: the apparent path of the Sun across the celestial sphere over the course of the year. The paths of the Moon and visible planets also remain close to the ecliptic, within the belt of the zodiac, which extends 8-9° north or south of the ecliptic, as measured in celestial latitude. Historically, these twelve divisions are called signs. Essentially, the zodiac is a celestial coordinate system, or more specifically an ecliptic coordinate system, which takes the ecliptic as the origin of latitude, and the position of the sun at vernal equinox as the origin of longitude.