Sun, Moon & Rising
Three familiar terms, three different roles within a birth chart.
The Sun sign refers to the zodiac section containing the Sun as seen from Earth for a particular moment. In the tropical system it is usually the first part of a chart people learn. Astrologers symbolically associate it with identity or direction, but there is no demonstrated scientific basis for using a Sun sign to predict personality.
The Moon sign is calculated from the Moon's celestial position at the same moment. It changes signs more often than the Sun. Traditional interpretations use it to discuss feelings, habits and the rhythms of everyday life, yet those meanings are cultural and interpretive rather than established measurements.
The rising sign, or ascendant, is the zodiac point where the ecliptic meets the eastern horizon. It depends strongly on location and precise time, because Earth rotates. A guessed or missing birth time can therefore make a rising sign unreliable. The geometry can be calculated; its alleged psychological significance is a separate matter.