This chapter explains the concept of corporate governance, tracing its conceptual foundations, theoretical underpinnings, structural mechanisms, and international applications. It begins by defining corporate governance as the system of rules, practices, and processes through which companies are directed and controlled, highlighting both narrow (internal controls and accountability) and broad (social, ethical, and environmental responsibilities) perspectives. The chapter elucidates key principles including accountability, transparency, fairness, responsibility, and stakeholder engagement which is supported by OECD, UK, and other global frameworks. Governance structures and mechanisms such as the board of directors, audit, remuneration, and nomination committees, risk management systems, internal and external audits are discussed in detail. Comparative analyses of corporate governance codes across the US, UK, Germany, Australia, Japan, and China reveal both shared principles and jurisdiction-specific differences. The chapter also addresses challenges such as conflicts of interest, regulatory inconsistencies, and digital-era risks, offering strategies for strengthening governance through diversity, ethical culture, technological investment, and active stakeholder engagement. It concludes that effective corporate governance is essential for organisational sustainability, investor confidence, and ethical corporate conduct.