The second set of dependencies are those required for JDBC database access:

    1. <dependency>
    3. </dependency>
    5.   <artifactId>hsqldb</artifactId>

    is well-known relational database that is written in Java. It is quite popular when used as an embedded database to avoid the requirement of having a third-party database server running separately. It is also popular for unit and integration testing as it offers a (volatile) in-memory storage.