JDBC connection basics  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.  Related concepts About Derby databases Tools
and localization