ESG (Environmental, Social, Governance) reporting is the practice of measuring and disclosing a company's impact across three dimensions: Environmental (carbon, water, waste), Social (labor practices, diversity, community), and Governance (board composition, ethics, compliance). There is no single ESG standard. Instead, multiple standards coexist: GRI (comprehensive), SASB (material issues by industry), TCFD (climate financial risk), EU CSRD (regulatory), and industry-specific frameworks. Companies typically report against multiple standards to satisfy different stakeholders.