Most of the Derby tools are JDBC applications. A JDBC application is one that uses the classes in the java.sql package to interact with a DBMS.
When you work with JDBC applications, you need to know about several concepts. The most basic is the connection. A JDBC connection is the object through which commands are sent to the Derby engine and responses are returned to the program. Establishing a connection to a specific database is done by specifying a appropriate database URL. The following sections provide background information to help in understanding the Derby database connection URL.