When explaining this in training courses I like to have a large flipchart with a vertical line down the middle. The left hand side is labelled "your_app.pl" and the right hand side is labelled "SomeModule.pm". I then draw in links between the two symbols tables to show how symbols from SomeModule are exported into your_app (or, alternatively, how your_app imports symbols from SomeModule).

All the time I'm leaping from side to side of the flipchart to demostrate how imports from one point of view are exactly the same thing as exports from the opposite point of view.