The Comptroller and Auditor-General (CAG) of India is a pivotal constitutional authority established under Article 148 of the Indian Constitution. As the supreme audit institution of India, the CAG plays a crucial role in upholding parliamentary democracy by ensuring financial accountability and transparency in governance. Its functions are broadly categorized into enhancing government accountability and acting as a watchdog of public finances.

Enhancing Accountability of the Government:

1. Comprehensive Audit Mandate: The CAG audits all receipts and expenditures of the Union and State governments, including bodies and authorities substantially financed by the government, government companies, and certain other corporations. This extensive mandate ensures that virtually all public spending is subject to scrutiny.
2. Performance and Propriety Audit: Beyond merely checking for financial regularity and compliance with rules, the CAG conducts performance audits to assess the economy, efficiency, and effectiveness of government programs and projects. It also examines the 'propriety' of expenditure, questioning whether funds were spent judiciously and for the intended public purpose.
3. Reporting to Parliament/State Legislatures: The CAG submits its audit reports to the President (for Union accounts) or the Governor (for State accounts), who then lays them before Parliament or the respective State Legislature. These reports are subsequently examined by parliamentary committees like the Public Accounts Committee (PAC) and the Committee on Public Undertakings (COPU). This process ensures that the executive's financial actions are scrutinized by the legislative branch, holding it accountable.
4. Transparency and Public Scrutiny: By bringing financial irregularities, wasteful expenditure, and instances of corruption to light through its reports, the CAG promotes transparency in government operations. These reports often become subjects of public debate and media attention, further enhancing accountability.

Serving as the Watchdog of the Finances of the Government:

1. Guardian of the Public Purse: The CAG is often referred to as the 'guardian of the public purse.' Its primary role is to ensure that public money is spent legally, efficiently, and for the purposes for which it was sanctioned. It acts as a check against arbitrary or unauthorized expenditure by the executive.
2. Constitutional Independence: The CAG's independence is safeguarded by constitutional provisions, including security of tenure, appointment by the President, and salary charged to the Consolidated Fund of India. This independence allows the CAG to perform its duties without fear or favor from the executive.
3. Checks on Executive Overreach: By scrutinizing government accounts and operations, the CAG acts as a vital check on the executive's financial powers. It ensures that the executive adheres to the financial rules and policies approved by the legislature, preventing misuse or diversion of funds.
4. Post-Facto Audit: While the CAG conducts post-facto audits (after the expenditure has occurred), its findings and recommendations significantly influence future financial discipline and policy-making. The fear of audit scrutiny acts as a deterrent against financial mismanagement.

Conclusion: The CAG is an indispensable institution in India's democratic framework. By meticulously auditing government accounts and operations, it not only enhances the accountability of the executive to the legislature and the public but also acts as a vigilant watchdog, safeguarding the integrity of public finances. Its independent and comprehensive scrutiny is crucial for promoting good governance, preventing corruption, and ensuring the judicious use of taxpayer money.