A Basic Service Demat Account (BSDA) suits investors with holdings under ₹2 lakh, offering zero AMC up to ₹50,000 and ₹100 + GST between ₹50,000 and ₹2 lakh. Only one BSDA is allowed per person. Regular Demat accounts have no holding limits but higher AMCs (₹300-₹800) and are ideal for active traders. Physical statements are free with BSDA.