1. At compilation time ,compiler won’t check whether our class contains main() method or not and whether it is properly declared or not.
  2. At runtime JVM is responsible to check main() method declaration.
  3. If main method is not available or it is not properly declared JVM will throw an error message saying NoSuchMethodError:main

JVM always checks main method with the following declaration .

public static void main(String[] args)

The below image explains main method in detail.
Main-method-explaination