Access Modifiers

In short: Access modifiers determine from where classes, methods and attributes may be accessed.

In more detail: Java has four levels: public, protected, package-private (no keyword) and private.

In Depth

Modifier	Class	Package	Subclass	Everywhere
public	yes	yes	yes	yes
protected	yes	yes	yes	no
(none)	yes	yes	no	no
private	yes	no	no	no

Why?

They ensure encapsulation: data should only be changed through controlled methods (getters and setters).

See getter, setter, abstraction.

See also: public, private, protected, Getter