Hash functions are the cryptographic glue of blockchains. They turn any data into a short, unique fingerprint (the hash). Blockchains use hash functions like SHA-256 and Keccak to secure transactions, blocks, and more.
Why is this important?
Hashes are used for transaction IDs, block hashes, and digital signatures.
They make sure data can’t be changed without detection.
Hash functions are fast, secure, and one-way (you can’t go backwards).
Real-world example: Bitcoin mining is a race to find a block hash with enough zeros at the start!