Don’t worry, it’s actually simple to understand.
The sky is a full circle of 360°, and around the Earth there’s an imaginary belt — about 16° wide — called the zodiac belt. Inside this belt are the 12 zodiac signs, each covering 30°.
Rising Sign (Ascendant) is the zodiac sign that was rising on the eastern horizon at the exact moment you were born.
This sign changes roughly every two hours, which is why accurate birth time is very important in Vedic astrology.
The Sun Sign is based on where the Sun was at the time of your birth.
The Sun moves about 1° per day, completing one full circle through all 12 signs in about 365.24 days.
So, in short:
Rising Sign → represents your body and outer personality
Moon Sign → shows your emotions and mind
Sun Sign → reflects your soul and life purpose
Most astrologers study all three because together they show the complete picture of who you are--body, mind, and soul.