Let's talk DAG! IOTA, Nano, Byteball & Hashgraph

Directed Acyclic Graph (DAG) is a "graph that flows in one direction where no element can be a child of itself" (source: https://medium.com/@hamzasurti/advanced-data-structures-part-1-directed-acyclic-graph-dag-c1d1145b5e5a) . The data structure's utilized are very different from the blockchain data structures utilized by most cryptocurrencies. A few crypto projects have elected to use DAG technology, namely IOTA, Nano, Byteball, and Hedera Hashgraph (not live yet) has also been working on it. P…