How does the astrological zodiac Capricorn compare with the astronomical Capricornus?

Answer 1

Way back when, people noticed that the sun passed through twelve constellations reliably throughout the course of the year. The twelve constellations were given significance as the zodiac and later had the astrological ideas attached to them (if I remember correctly, our modern ideas of astrology came about during the Renaissance). So, they correlate directly.