What is a Parameter?
Is a setting that determines the appearance of a behavior of a element, type, or view.
Are user defined fields that you add to families. They are stored in the family file, and cannot be used in any other element apart from the family it was created in.
Are user defined fields that you add to families or projects and then share with other families and projects. They are stored in a file independently of the family file or Revit Project. This allows you to access the file from different families in our projects. Shared parameters also can be used in tags for model elements, and they can display in schedules.
Settings that control the appearance or behavior of a particular family type. A type parameter affects all instances (individual elements) of that family in the project and any future instances that you place in the project.
Settings that control the appearance or behavior of and individual element in a project.
Suppose you select a pump and click (Element Properties). You change one of the instance parameters and click OK. Only that pump is affected, even if the project contains other instances of other individual pumps of the same type.