As I stated before, all applets must extend the Applet class. Before we can extend a class, we must first import that class. Therefore, all applets must import the Applet class. DragonClock must paint the clock to the computer screen. We must extend the Graphics class in order to do that.
Graphics is part of the awt class.
So therefore it is the awt class that must be imported. DragonClock must also import java.util.Calendar in order to grab the current time. So we must import that class also. The very first lines of an applet are devoted to importing the necessary classes for the program. Once we import the necessary classes, we can declare our own class and begin writing the applet.