Non-relational databases, also known as NoSQL databases, are designed to store and manage data in ways that differ from traditional relational databases. Instead of using tables with fixed schemas, non-relational databases can handle unstructured or semi-structured data, allowing for greater flexibility. They often use formats like key-value pairs, documents, or graphs to organize information, making them suitable for applications that require scalability and rapid data retrieval. These databases are particularly useful for big data applications and real-time web services, where the volume and variety of data can be overwhelming. Popular examples of non-relational databases include MongoDB, Cassandra, and Redis. Their ability to scale horizontally makes them ideal for cloud-based environments and modern software development practices.