The 1.0 release of the Java language supported five access levels: the four discussed here, plus private protected. The private protected access level is not supported in versions of Java higher than 1.0; you should no longer be using it in your Java programs

Java allows the programmer to specify the visibility of classes and of fields and methods within classes by specifying access privileges. Using the right access modifier, a programmer can use encapsulation to hide data from those parts of a program where visibility is not needed while allowing access where required.