Goods and Services Tax (GST) is a comprehensive, multi-stage, destination-based indirect tax that is levied on the supply of goods and services across India, replacing a complex and fragmented system of multiple central and state taxes that previously created significant economic inefficiencies and compliance burdens. Implemented on July 1, 2017, following the passage of the 101st Constitutional Amendment Act of 2016, GST represents one of the most significant and transformative tax reforms in India's post-independence history. Often described as "One Nation, One Tax, One Market," GST was designed to unify the Indian economy by eliminating the cascading effect of multiple taxes, reducing the overall tax burden on consumers, simplifying compliance procedures for businesses, and creating a seamless national market for goods and services across all states and union territories.GST in India operates on a dual structure, with both the Central Government and State Governments simultaneously levying taxes on goods and services. Central GST (CGST) is collected by the Central Government, State GST (SGST) is collected by the respective State Governments, and Integrated GST (IGST) is levied by the Central Government on inter-state transactions and imports. Goods and services are classified under four primary tax slabs — 5%, 12%, 18%, and 28% — based on their nature and necessity. Essential commodities such as food grains, fresh vegetables, and life-saving medicines are either exempt from GST or taxed at lower rates, while luxury goods and demerit goods such as tobacco products, aerated beverages, and high-end automobiles attract the highest rates along with an additional cess. The GST Council, a constitutional body comprising the Union Finance Minister and Finance Ministers of all states, is responsible for making recommendations on tax rates, exemptions, and policy changes, ensuring cooperative federalism in tax administration.The implementation of GST has brought several significant benefits to the Indian economy and business environment. By replacing over a dozen central and state taxes — including Central Excise Duty, Service Tax, Value Added Tax, and Octroi — GST has dramatically simplified the indirect tax structure and reduced the compliance burden for businesses. The Input Tax Credit (ITC) mechanism, which allows businesses to offset the GST paid on inputs against the GST collected on outputs, eliminates the cascading effect of taxes and reduces the overall cost of production. The GST Network (GSTN), a technology platform enabling online registration, return filing, and tax payment, has significantly improved transparency and reduced opportunities for tax evasion. However, GST implementation has also faced challenges, including the complexity of compliance for small and medium enterprises, frequent changes in tax rates, technical glitches in the GSTN portal, and ongoing disputes between the Centre and states over revenue sharing. Despite these challenges, GST has progressively strengthened India's tax base, improved revenue collection, and contributed to greater formalization of the economy, representing a landmark step in the ongoing reform of India's fiscal architecture.