Illustrate vs. Demonstrate

####Illustrate
To show or make something clearer (or more interesting) by using pictures , diagrams or
examples.

EXAMPLES:
This diagram illustrates the position of the body’s main organs.
The speaker illustrated his point with an amusing anecdote/example/story.

####Demonstrate
(1) To show or explain through actions
(2) To provide evidence that proves something.

EXAMPLES:
First, the instructor demonstrated the move herself; then she told us to try it.
The accident demonstrates the need for improvements to the road.