The Planning Commission of India was replaced by NITI Aayog in 2015 to promote cooperative federalism, address the diverse needs of states, and transform India into a global competitive economy. Key differences include NITI Aayog functioning as a think tank rather than allocating funds, encouraging participation from states in policymaking, and focusing on evidence-based strategic policy frameworks. It aims to foster multi-directional policy flows between central and state governments to achieve equitable development through collaborative efforts.