Difference between Protected and Default members - Java

The protected and default access control levels are almost identical with one critical difference. A default memeber can be accessed only if the class accessing the members belong to the same package, whereas a protected member can be accessed [only through inheritence] by a sub class even if the subclass is in a different package.

Java Access Modifiers/Access Level

Access Level/Modifiers	Public	Protected	Default	Private
From the same class	Yes	Yes	Yes	Yes
From any class in the same package	Yes	Yes	Yes	No
From a subclass in the same package	Yes	Yes	Yes	No
From a subclass outside the same package	Yes	Yes, using inheritance	No	No
From a any non-subclass outside the package	Yes	No	No	No

Java - why public static void main

public: The public method can be accessed outside the class or package.

static: To access the static method, there is no need to create object and you need not have an instance of the class to access the method.

void: There is no need by application to return value. JVM launcher do this with it exists.

main(): It is the entry point for the java application.

String args[] : args is an array of string which holds the optional arguments to the class.