What is Tangle?

The Tangle is a Directed Acyclic Graph (DAG)-based distributed ledger architecture used by the IOTA network, fundamentally different from traditional blockchain structures. Instead of blocks containing multiple transactions being appended to a chain, each transaction in the Tangle directly references and approves two previous transactions, forming a DAG. When a user wants to submit a transaction, they must perform a small amount of proof-of-work and validate two previous unconfirmed transactions (called "tips"), contributing to the network's security in exchange for having their own transaction processed. This creates a self-regulating system where the more transactions are submitted, the faster previous transactions are confirmed, theoretically enabling the network to scale with increased usage.

The Tangle's architecture provides feeless transactions — since each participant validates two previous transactions as part of submitting their own, there is no need for miners or validators who require fees. This makes it particularly suitable for micropayments and IoT (Internet of Things) applications where transaction fees would be prohibitive. The original Tangle design used a Coordinator (a centralized node operated by the IOTA Foundation) as a finality mechanism to protect the network during its early growth phase when low transaction volume made it vulnerable to attacks. The ongoing development toward "Coordicide" (removing the Coordinator) aims to make the network fully decentralized, with committee-based voting and other mechanisms replacing the centralized finality checkpoint.

The Tangle has been running on the IOTA network since its launch in 2016, founded by David Sonstebo, Sergey Ivancheglo, Dominik Schiener, and Serguei Popov. IOTA has positioned itself as the ledger for the Internet of Things, targeting machine-to-machine payments and data integrity applications. The IOTA Foundation has partnered with various industrial and governmental organizations to explore IoT and supply chain use cases. The network has undergone significant protocol evolution, with the Chrysalis upgrade improving usability and the ongoing Stardust/IOTA 2.0 development working toward full decentralization. The Shimmer network serves as IOTA's staging network where new protocol features, including the decentralized consensus mechanisms, are tested before deployment to the main IOTA network.