Databases are critical for storing, organizing, and retrieving data, with the two primary types being relational (SQL) and non-relational (NoSQL) databases. Relational databases structure data in tables linked by primary and foreign keys, making them ideal for complex data management and applications requiring data consistency and complex queries. In contrast, non-relational databases are designed for unstructured or semi-structured data, offering flexibility, scalability, and high performance, and are suitable for applications with large data volumes and less rigid data requirements. Examples of relational databases include MySQL and Oracle Database, while MongoDB and Apache Cassandra exemplify non-relational databases. The choice between these databases depends on factors like data type, scalability needs, and application requirements, with each offering unique features and benefits that cater to different types of data and application demands.