Directed Acyclic Graph (DAG)
A ledger structure that links transactions in a branching web rather than a single chain of blocks.
A directed acyclic graph drops the idea of one block following another in a line. Instead, each new transaction references one or more earlier ones, forming a web that only moves forward and never loops back. There is no single chain and, in pure designs, no miners.
Projects like IOTA and Hedera use DAG-based ledgers, pitching them for high throughput and tiny fees. The approach is less battle-tested than Bitcoin's chain. Achieving solid security and ordering on a DAG without some central coordinator has proven harder than early promises suggested.
Related terms
A shared digital ledger that records transactions in linked batches, copied across many computers and hard to alter.
ScalabilityA network's capacity to handle more transactions and users without fees and delays spiking.
Distributed Ledger Technology (DLT)The broad category of systems that keep a synchronized record across many sites with no central master copy.