Extending Applet implements Runnable --explain

Question

kindly give an explanation of the need to use the
<extends Applet implements Runnable > code
while creating an applet program is there a need to use both Applets and Runnable
wht are the methods available in Applet class
and Runnable interface

Answer 1

The most common use of the Runnable interface is for threading.
An applet doesn't need to implement Runnable to be run as an Applet, but an applet often needs to be doing things in the background, not just when specific user events like init, start, mouse events etc. come in. For example the applet might run some kind of animation.
An applet should return promptly from events of the above sort, allowing the browser to get on with it's own business. If it is to do something itself one of these events needs to start a thread.
Declaring the Applet runnable allows you to do something like:
new Thread(this).start();for example in the init method. This starts a new thread of execution which runs the run method of the applet, which will do the background activity.
You don't have to do it this way, you can create another Runnable object whose run method will be executed by the thread. Often you use anonymous classes for this e.g.
new Thread(new Runnable() {
   public void run() {
          doBackgroudStuff();
    }).start();