Wrapper class: A wrapper class is a class that provides an object representation for each of the primitive data types in Java. For example, the Integer class is the wrapper class for int.
Autoboxing: Autoboxing is the automatic conversion that Java does between primitive types and their corresponding wrapper classes. For example, when assigning an int value to an Integer variable, autoboxing automatically converts it into an Integer object.
Unboxing: Unboxing is the opposite of autoboxing - it's when Java automatically converts an object of a wrapper type back to its corresponding primitive type. For example, extracting the int value from an Integer object.