The coding documentation is very necessary and useful because it ensures the longevity and usefulness of the component. In additional, this documentation can be used again while it is needed. It is helpful in the larger team environment and the confusions and purpose of the code can be alleviated easily.
In coldfusion framework, the development of custom meta data is provided to the end user and developer. The purpose of creating the metadata in a method (function) is to provide the value to the function developed by the application developer. It enhances the documentation availability of the application.
The biggest quality of the meta attributes is that they have no impact on the working of properties, functions and methods. They also cannot be viewed by the CFC explorer in introspection. The meta data usually shows the information pertaining the object. There are 2 methods to show the metadata -
getmetadata ()
getcomponentmetadata ()
getmetadata () is used to retrieve the metadata attributes of any functions defined in the application. In the parameter of the function, the expression of an object is passed as a parameter.   
getcomponentmetadata () is used to retrieve the metadata of an object, functions, properties and methods and it is similar to the working of getmetadata (). The overall difference is that this method can also be used to take the instance of the object which isn’t defined.

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