Exposition is an explanation of necessary information to the understanding of the facts from which the story action departs.
Basically, it’s a lot of dialogue (usually a monologue or speech) that explains something we need to know. But the reality is that most real talk doesn’t work this way. We don’t stand up and blah, blah, blah our talking points to shed crystal clear light on an issue or situation.
Real talk is disjointed, redundant, and unfocused. Besides, exposition almost always seems forced, unless… the character’s occupation itself requires him or her to explain things.
Lawyers, Judges, Professors, Police Officers, and Scientists all clarify information on and off the job. In fact, any professional who’s an expert in something does just the same. This is why it’s wise for you to create characters whom specialize in a specific field, so when there comes a time to explain, your character can easily put on the professional hat and tell us exactly what we need to know.