Why is blockchain important because it offers a secure, transparent, and decentralized method for recording and verifying transactions without the need for intermediaries. Its key feature—immutability—ensures that once data is recorded, it cannot be altered or deleted, providing a high level of trust. Blockchain increases efficiency by reducing transaction costs and time delays. It has applications across industries such as finance (DeFi), healthcare, supply chain, and voting systems, providing a foundation for digital innovation, fraud prevention, and ensuring data integrity in an increasingly digital world.