IOTA is a cryptocurrency that was created in 2015 and is based on a technology called the Tangle. The Tangle is a distributed ledger technology that is different from the blockchain used by most cryptocurrencies. It uses a directed acyclic graph (DAG) to store transactions, rather than a linear chain of blocks.

One of the key features of IOTA is that it is designed to be used in the Internet of Things (IoT) ecosystem. It aims to provide a feeless and scalable infrastructure for the IoT, allowing devices to exchange data and value without the need for intermediaries.

IOTA also uses a consensus mechanism called the Coordinator, which is a centralized component that is used to protect the network in its early stages. The goal is to eventually remove the Coordinator and have a fully decentralized network.

In addition to its use in the IoT ecosystem, IOTA has also been used for other applications such as supply chain management, digital identity, and micropayments.