In blockchains, every transaction is turned into a unique digital fingerprint called a hash. This hash is created using a cryptographic hash function (like SHA-256) and is used to identify, secure, and verify transactions.
Why is this important?
Hashes make sure no one can secretly change a transaction.
They are used as transaction IDs in Bitcoin, Ethereum, and other blockchains.
Even a tiny change in the transaction creates a completely different hash.
Real-world example: When you look up a transaction on a block explorer, you use its hash!