Element Properties vs. Type Properties

Understand the difference between Element Properties and Type Properties early. Element properties are unique to selected elements (eg. height of a wall). Type Properties control every instance of a type of object (eg. width of a wall). The more often a property is to vary per element, the more likely it may be considered an element property.

Note:

Element properties = Instance parameters

Type properties = Type parameters (As for the naming variation between the two, all I can suggest is "Go figure").