IOTA is a next generation permissionless distributed ledger that utilizes a novel invention, called a 'Tangle', at its core. The Tangle is a new data structure based on a Directed Acyclic Graph. As such it has no Blocks, no Chain and also no Miners. This radical new architecture enables things in IOTA work quite differently compared to Blockchains and other Distributed Ledger Technologies.
Apart from the data structure, the other major difference is how IOTA achieves consensus and how transactions are made. As mentioned previously, there are no miners. What this means is that each participant in the network that wants to make a transaction has to actively participate in the consensus of the network by approving 2 past transactions. This attestation on the validity of two past transactions ensures that the network achieves consensus on the current state of approved transactions, and it enables a variety of unique features that are only seen in IOTA.
IOTA has a range of features that are uniquely enabled due to its architecture:
Please visit the official documentation on The Tangle at: https://docs.iota.org/introduction