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. Because the divisions are regular, they do not correspond exactly to the boundaries of the twelve constellations after which they are named.

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.

https://en.wikipedia.org/wiki/Zodiac

"There are all kinds of interesting questions that come from a knowledge of science, which only adds to the excitement and mystery and awe of a flower."
Richard Feynman
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