Hyphens are used between words to avoid confusion in a sentence. They can be used to show which word is an adjective.
A single dash can be used in the middle of a sentence to show a sharp break in the flow of words. It can be used to mark a dramatic pause before saying something surprising or exciting.
Brackets can be used to add additional information or an explanation to a sentence to give greater detail, expand on an abbreviation or provide a time, date or place.