India Stack is a comprehensive digital public infrastructure developed by the Government of India to facilitate digital transformation and enhance service delivery. It is a set of open APIs and digital infrastructure that aims to enable identity verification, digital payments, paperless governance, and secure data sharing. The stack includes key components such as Aadhaar (identity verification), UPI (payments), eSign (digital signatures), DigiLocker (document storage), and e-KYC (know your customer), which collectively enable businesses and government services to operate efficiently in the digital space. It has been used for everything from financial inclusion (like subsidies) to online banking and digital signatures for contracts.