Non-relational databases, also known as NoSQL databases, store data differently from traditional relational databases. They do not rely on structured tables with fixed columns and rows, which makes them more flexible. In the context of decentralized systems, non-relational databases can efficiently manage diverse, unstructured, or semi-structured data types. This includes user transactions, smart contracts, and real-time data feeds. The ability to scale horizontally allows them to handle vast amounts of data without performance loss, making them suitable for dynamic environments like blockchain and related applications.These databases support various data models, such as document, key-value, graph, and column-family stores. This variety enables developers to choose the best structure depending on their needs. For instance, a key-value store might be used for quick access to user wallets, while a document-oriented database might serve smart contracts.Overall, non-relational databases offer the flexibility and scalability needed for building applications that handle large amounts of varied data, making them a crucial component in many projects.