Information conveys states of mind, states of existence, but not states of affairs (unless you’re dramatizing the past via a flashback, but that’s not conveying the present-time story state of affairs). But if your information (facts, past, interiority, context) is not relevant to the story’s state of affairs, your reader is going to tune it out—or worse, come to distrust your narration.
External refers to what’s happening outside of characters’ minds. It’s the stuff that an observer could see. You could film it pretty easily. Internal refers to what’s going on inside a character’s head: feelings and thoughts. Prose storytelling regularly informs us of characters’ interiority in ways that, say, a screenplay cannot.
I recently came across this insightful analysis of suspense in the opening of the film Inglorious Basterds. In it, there’s a mention of an article from the Psychology journal, Frontiers in Psychology about Tension and Suspense. The authors, Moritz Lehne and Stefan Koelsch, posit six components underlying suspense and tension, which I find useful in thinking about crafting scenes to engage your readers and get your characters into trouble.