What is Merkle Tree?

A Merkle tree is a hierarchical structure where every leaf is a hash of data and every parent is a hash of its children producing a single root hash that fingerprints the entire dataset.

How does Merkle Tree work?

Transactions are hashed individually, then pairs are hashed together, repeating upward until one Merkle root remains. Any change to any transaction changes the root entirely.

Why does Merkle Tree matter?

They let nodes verify data integrity by checking a small fraction of the total data, enabling mobile light clients and making blockchains scalable.

Key features of Merkle Tree

Single root hash represents all data
Any change invalidates the root
Enables efficient data verification
Foundational for light clients and Layer 2

Examples of Merkle Tree

Bitcoin summarizes thousands of transactions into a single 32-byte Merkle root per block. Light clients download only 80-byte headers and use Merkle trees to verify specific transactions.