Java: Boolean (class) vs boolean (primitive)

A Boolean is a class, or a reference type, defined in the standard library. It stores a reference to an object containing a value (a "box").

A boolean on the other hand, is a primitive type and part of the language itself. It stores an actual value.

We say that Boolean is the wrapper type for boolean, and objects of type Boolean are boxed values.

Continue reading here:

Java: Primitives vs Objects and References
Java: Wrapper Types