Juxtaposition is the deliberate placing of two contrasting words or concepts next to each other, in order to create a stark comparison. It is very often done in writing in order to highlight their differences.Common examples include light and dark, good and evil, "It was the best of times, it was the worst of times" (Charles Dickens, A Tale of Two Cities)This doesn't have to be in writing either; if a waiter gave you a plate in a restaurant with a pork chop and a chocolate cake on it, you would note the juxtaposition of the two very different foods.