According to classical Vedic astrology and the BPHS tradition, Mercury signifies intelligence, speech, learning, analysis, commerce, writing, and communication. It shows how a person thinks, processes information, speaks, reasons, and adapts to changing situations. A strong Mercury can give sharp intellect, wit, skill in language, business ability, and practical judgment, while an afflicted Mercury may create confusion, nervousness, miscommunication, inconsistency, or poor decision-making. Mercury is essential for understanding the rational mind, expression, calculation, and everyday mental functioning in a birth chart.