What is the difference between the private and protected access modifiers in Java?

In Java, private and protected are two of the four access modifiers that control the visibility of a class, method, or variable in a program. They specify how the members of a class can be accessed from outside the class.

Private Access Modifier: If a method or variable is declared as private, it can be accessed only within the same class. The member is not visible outside the class and cannot be accessed by subclasses or other classes in the same package.

Protected Access Modifier: If a method or variable is declared as protected, it can be accessed within the same class, subclasses, and other classes in the same package. However, it is not visible to classes in other packages.

The difference between private and protected is in the level of access they provide. Private provides the strictest level of access and is used to hide the implementation details of a class from other classes. Protected provides a less strict level of access and is used to allow subclasses and other classes in the same package to access the member.