Tangle is the moniker used to describe IOTA’s Directed Acyclic Graph (DAG) based transaction settlement and data integrity layer focused on the Internet of Things (IOT). The Tangle is essentially a string of individual transactions that are interlinked to each other and stored through a decentralized network of node participants.
Importantly, the Tangle does not have miners as users of the network function as the miners themselves through performing small computational Proof of Work (PoW) for each transaction by verifying previous transactions submitted to the network. Focused on allowing the network to scale for a global micropayment network of interconnected IoT devices, The Tangle is designed to offer a solution to the heterogeneous nature of current blockchain systems.
Source: What is The Tangle? Complete Guide to IOTA’s Directed Acyclic Graph (DAG)