The main function stands for the main thread.
Singleton is to ensure there is only a single instance of a class in our app.
To create an interface, we use the same way as we created a class. Just right click on the package →”New” →”Java Class” →”Interface”
As mentioned previously, in order to create a class, we right click on the package → “New” → “Java Class”, and name the class.
Notes from the video: https://www.youtube.com/watch?v=fis26HvvDII&t=358s