Copy
Scales and copies the elements in the selection set.
Step
Specifies the step value for the Scale Factor. The step value causes the Scale Factor to decrease or increase in increments as you move the cursor toward or away from the scale origin. For example, if you set the step value to 0.25, the scale increases in increments of 0.25 as you move the cursor away from the scale origin.
Scale Factor
Specifies how much the software reduces or enlarges the element. A scale factor between zero and one reduces; a scale factor greater than one enlarges.
Reference
Specifies how long the dynamic line from the scale origin to the mouse cursor has to be in order to achieve a Scale Factor of 1.
For example, if you set Reference to 1, for every inch you move the cursor away from the scale origin, the scale factor increases by one. If you set Reference to 2, for every two inches you move the cursor away from the scale origin, the scale factor increases by one.