Supply in the Course or Furtherance of Business determines whether a transaction is a taxable supply under GST law. Whether a transaction is a taxable Supply under GST depends on if it is made 'in the course or furtherance of business,' with 'business' under section 2(17) broadly including trade, professions, ancillary activities and one off vocational sales. Incidental disposals by a commercial entity are treated as in the course of business, while personal disposals or regulatory activities of dominant non commercial purpose may not be. Eligibility for Input Tax Credit similarly requires that inputs, input services and capital goods be used or intended to be used in the course or furtherance of business.