In Java, a wrapper class is a class that encapsulates a primitive data type within an object. It provides a way to convert a primitive data type to an object and manipulate the value in a more flexible way.

There are eight primitive data types in Java, including byte, short, int, long, float, double, boolean, and char. Each of these data types has a corresponding wrapper class. The wrapper classes are Byte, Short, Integer, Long, Float, Double, Boolean, and Character, respectively.

Wrapper classes offer several benefits, such as providing utility methods that can be used to convert, compare, and manipulate values. Additionally, they can be used in collections and data structures that require objects.

One important feature of wrapper classes is autoboxing and unboxing. Autoboxing automatically converts a primitive data type to its corresponding wrapper class when necessary, while unboxing converts a wrapper class back to its primitive data type. This feature can simplify code and make it more readable.

In summary, wrapper classes in Java provide a way to encapsulate primitive data types within objects, making them more flexible and providing utility methods. They also offer autoboxing and unboxing, which can simplify code.