Render 2D Images (bitmaps, targa, etc..)

A wrapper is a class interface to an API usually (like OpenGL).

A wrapper is usually much more thin than an Engine. An engine usually consists of more helpful things rather than just a layer around an API. A wrapper could be a class interface to OpenGL Functions and an Engine would be able to load images, store them correctly and display them when needed, do the proper timing, hold the images in an array or linked list, load the images at the start of a map.

EDIT: what all connects these together is usually what you discuss in the planning stage of developing an engine. You go through the relations of each component of the engine and how they effect each other.

Example: for a a CWorld class you would need to display or manage the enemies and the player in the world so it is safe to assume that CWorld will somewhat manage the entities or at least their positions.