Assertive communication involves expressing one's thoughts, feelings, and beliefs in a way that respects others and does not compromise one's own rights and boundaries. It allows one to achieve their goals without creating conflict. Aggressive communication, on the other hand, involves expressing oneself without consideration for how it impacts others. It can be harsh, disrespectful, and hurtful. Examples provided contrast how one might assertively decline a request compared to aggressively denying it.