Beyond Blockchain: The Role of IOTA in IoT Applications

The rapid expansion of the Internet of Things has transformed industries by enabling seamless data exchange across devices and systems. However, this growth also introduces critical challenges in security, scalability, and interoperability. This paper examines how distributed ledger technologies, particularly blockchain and IOTA, address these issues. IOTA's Tangle, enables feeless transactions, low energy consumption, and high scalability, making it well-suited for microtransactions. Blockchain, by contrast, offers decentralization, immutability, and strong data integrity. We explore their applications in supply chains, healthcare, digital twins, and network management, while also highlighting limitations such as IOTA's former reliance on a coordinator, the introduction of fees in IOTA Re-based, and privacy risks. By synthesizing recent literature, this review outlines the current landscape, key challenges, and future research directions for applying IOTA in IoT ecosystems.