Above the line (ATL) and below the line (BTL) are advertising strategies that target different audiences; ATL uses mass media to engage a broad audience, while BTL focuses on direct, one-to-one interactions for specific consumer engagement. ATL typically includes traditional media like TV, radio, and print, whereas BTL encompasses personalized methods such as pamphlets, product demonstrations, and direct mail campaigns. Companies may prefer BTL for budget constraints and the need for experiential marketing.