Short answer
Your Moon sign (Rashi) is the sign the Moon occupied when you were born; your Sun sign is the Sun's sign. The Sun changes sign about once a month, but the Moon moves on every 2.25 days or so, so you need your birth time to be sure. Vedic astrology centres on the Moon sign for forecasts, Sade Sati and transits.
How ChiChakra reads this
ChiChakra calculates your Moon sign in the sidereal zodiac using the Lahiri ayanamsa, about 24°14′ in November 2026. That offset is why your Vedic Sun sign is usually one sign behind your Western one for most of each month, and why your Vedic and Western profiles can look unrelated.
What each one tells you
The Moon describes the mind, feelings and day-to-day reactions. Because it moves quickly, it is also the reference point for Gochara (transit) forecasts.
The Sun describes core identity, vitality and your relationship with authority. It matters in the chart but is not the reference for most Vedic predictions.
Together with the Lagna (Ascendant), they form the three main anchors of a chart.
Good to know
If the Moon was close to changing sign when you were born, the finder flags it; an exact birth time settles the question.