# Merkle Tree A **Merkle Tree** can be defined as: > The content being hashed may also contain hash digests of other content; therefore, any content "address" authenticates content "linked" via the inclusion of their digest in the tree below it ### Merkle Trees as DAGs Note that we can consider a Merkle Tree to be a DAG because: * **Direction**: A hash function is irreversable, meaning it only has one direction. In other words: `hash_function(Data) -> Data` * **No cycles**: You can't link to content that doesn't already exist --- Date: 20211023 Links to: [Content-Addressable-Systems](Content-Addressable-Systems.md) Tags: References: * [Wikipedia](https://en.wikipedia.org/wiki/Merkle_tree) * [Great youtube talk](https://youtu.be/VtzpJU4Cns8?t=230)