An application and the applet may seem similar in the beginning but the application is something that can be executed by Java and will have the ability to stand alone. This is highly different from the applet that would need a web browser so that it will work. When you use a machine and what you are using works, this is an application.
If you would need to open a website before something works, then you may be looking at an applet. Another difference between the two is the size. The applet is known to be small while the application is large. Some people may choose not to download applications on their devices because the size of the application is too big.