The main Method

public so the JVM can access it from outside, static so no object is needed, void because there is no caller to return to. String[] args receives command-line arguments.

Yes, main can be overloaded with different parameter types. But the JVM always calls the String[] version as the entry point. The others are just regular methods.

No. Static methods cannot be overridden – they are resolved by the class, not the object. A subclass can define its own main, but it hides the parent's rather than overriding it.

Yes. Multiple classes can each have main(String[] args). You choose which one to run by specifying the class name. In a jar, the MANIFEST.MF Main-Class attribute selects the default.

Yes. String... args is compiled to the same bytecode as String[] args, so the JVM accepts it as a valid entry point. But the convention is to use String[] args.