This chapter aims to present the conceptualization of nudging developed by Thaler and Sunstein. Behavioural economics’ approach deviates from pure rationality since real people suffer from a variety of cognitive biases, including lack of self-control, excessive optimism, status quo bias, and susceptibility to framing of decisions, among others. Against the rational homo economicus, Thaler and Sunstein consider many false heuristics and biases that explain the gap between our good intentions and actual human behaviour. Therefore, human behaviour and choice exhibit bounded rationality, bounded self-interest, and bounded willpower. What behavioural economics clearly enunciates is that human behaviour and economic decisions are vulnerable to framing effects. The, nudges are considered to be social norms that can help people act rationally and, as Thaler and Sunstein claim, the possibilities for nudges are everywhere.