Watch this video in context on Unity's learning pages here - http://unity3d.com/learn/tutorials/modules/intermediate/editor/drawdefaultinspector-function
The DrawDefaultInspector function allows us to easily recreate the default inspector for a script inside a custom inspector. This is very useful if we only want to add new items to the inspector for a script instead of changing the currently existing items. In this video you will learn how to use the DrawDefaultInspector function.