What is the use of loadable families in revit projects? Although we can create instance families in project.

components cad directly use for the project instance of creating new. 

The main difference is in file size, multiplying loadable families will have a minor impact on the file size, but creating and using instance families will make your file much bigger. 

because the family have more Characteristics

Hi! loadable families it is a loadable components that use to import in your project . In create instance you have to make your own component to be loaded in specific project that you created.