Java DB is a relational database management system that is based on the Java programming language and SQL. Java DB is the Oracle release of the Apache Derby project, the Apache Software Foundation's (ASF) open source relational database project.
The Java DB product includes Derby without any modification whatsoever to the underlying source code.
Because Java DB and Derby have the same functionality, the Java DB documentation refers to the core functionality as Derby.
Java DB Version 10.6 is based on the Version 10.6 release of Derby. References to "Derby" in the Java DB documentation refer to the Version 10.6 release of Apache Derby.