public-private-protected-default defaults for differences

Public
Public, plus the properties and methods of this modification, can be accessed anywhere else in the program .

Private
Private, as opposed to public, with this modified property and method, is only allowed in this class to access .

Protected
Protection, located in the middle of public and private, plus the modified properties and methods, can only be accessed in subclasses (extends) and programs under the same package .

There is also a default (that is, without any modification)
The default, located in the middle of private and protected, plus the modified properties and methods, can only be accessed by programs under the same package .

public-private-protected-default defaults for differences