Run-time Representation
As a data type, a class is usually considered as a compile-time construct. A language may also support prototype or factory metaobjects that represent run-time information about classes, or even represent metadata that provides access to reflection facilities and ability to manipulate data structure formats at run-time. Many languages distinguish this kind of run-time type information about classes from a class on the basis that the information is not needed at run-time. Some dynamic languages do not make strict distinctions between run-time and compile-time constructs, and therefore may not distinguish between metaobjects and classes.
For example, if Human is a metaobject representing the class Person, then instances of class Person can be created by using the facilities of the Human metaobject.
Read more about this topic: Class (computer Programming)