Collections: Sets of objects. Objects within the set are referenced by their index in the set.
External objects: Objects that can be brought into PowerPoint using the Insert Object dialog. This includes pictures, sounds, movies, etc.
Master Coordinates: The reference system used by PowerPoint to put all objects on the screen. The origin for the system is the center of the slide. There are two axes, X (horizontal) and Y (vertical). Values on the X axis increase when you move to the right and the origin is 0. Values on the Y axis increase when moving down. Master coordinates are always 576 dpi.
View: Refers to the way a presentation is seen on the screen at a particular moment. This includes the current view, whether the guides or rulers are visible, and the view scale.