Final answer:
The invisible hand refers to the notion that self-interested actions in a competitive market can promote the social interest.
Step-by-step explanation:
The invisible hand refers to the notion that, under competition, decisions motivated by self-interest promote the social interest. It suggests that individuals pursuing their own interests in a competitive market will inadvertently promote the greater good for society as a whole. This concept was introduced by economist Adam Smith to explain the benefits of free markets and the role of self-interest in economic decision-making.