The Protected keyword in Java deals with the level of access.
For what? Concerning Variable, Methods, an Constructors that are declared as protected in a superclass.
Does what? can be accessed only by the subclasses in other package or any class within the package of the protected member’s class.
Not for? The protected access modifier cannot be applied to class and interfaces.
Methods and Fields can be declared protected.
However methods and fields in a interface cannot be declared protected.
TL;DR: Protected allows the subclass access, but no access for classes in a different package (to the Protected member’s package).