Technically speaking, DualShield server is a Java server application running in a Java server container called Tomcat. Tomcat runs in the Java Virtual Machine (JVM), and JVM runs in the machine's Operating System such as Windows or Linux OS.
DualShield server uses a standard SQL server as its data store. By default, it includes an instance of MySQL server.
The term "DualShield Framwork" is used to describe the set of software, namely JVM, Tomcat and MySQL, that can be technically seperated from the core of the DualShield software.