Astronomy describes the motion. Astrology is a system for reading meaning into it.
For most of recorded history the study of where the planets are and the study of what their positions meant were the same discipline. They separated around the seventeenth century. Astronomy kept the measurements. Astrology kept the interpretation.
This site is built on that split, and does not try to hide it. Every position on your chart is computed from the Swiss Ephemeris and agrees with NASA's own numbers to a fraction of an arcsecond. What those positions mean is a separate question, and a much softer one.
The view is from here
You were taught the heliocentric model: the Sun at the centre, the Earth going round it. That is the correct description of the mechanics. But astrology describes the sky as seen from the ground, which makes it geocentric, not as a claim about physics but as a choice of vantage point. Both models predict the same apparent motion, because they describe the same motion from two different places.
The zodiac is a band of constellations
The Sun, Moon and planets all travel within a narrow strip of sky, because the solar system is close to flat. Twelve constellations sit along that strip. From Earth, every planet always appears in front of one of them, and works its way through all twelve before starting again.
Modern Western astrology divides that band into twelve equal 30° segments measured from the March equinox, rather than using the ragged real outlines of the constellations. That is the tropical zodiac, and it is what this site computes.