Considering the data-centrality vision of our modern economy, it is natural to think whether or not it is possible to use a Distributed Ledger structure for the storage of general purpose data (or sensitive encrypted data) and not only financial transaction data.For my thesis I have chosen to study and analyze IOTA, a DLT created specifically for the IoT and focused on the data granularity. IOTA is called "a Blockchain without Block and without Chain" because it promises the same advantages of a Blockchain using, however, a different structure called Tangle.The tangle is basically a Directed Acyclic Graph (DAG) where, instead of building a chain of blocks added at specific intervals, transactions are sent directly, and each one becomes a node of the graph.