A Java Card application is called a Java Card applet. Although they have the same name, the only thing a Java Card applet and a Java applet have in common is that both are objects. An arbitrary number of classes and interfaces may compose an applet, as long as one of the classes extends javacard.framework.Applet. These classes and interfaces need to be stored in a package, which the converter transforms into a unique CAP file. The converter will also assign an AID (Application Identifier) to the applet. The CAP file may then be loaded and the applet may be instantiated. The applet may then be selected using its AID and sent commands to.