System 2 refers to a mode of thinking that is deliberate, analytical, and effortful. It is often contrasted with System 1, which operates automatically and quickly. When using System 2, individuals engage in critical thinking, problem-solving, and decision-making that require more cognitive resources and attention. This system is activated when faced with complex tasks or unfamiliar situations, such as solving a math problem or making a significant life choice. While System 2 can lead to more accurate conclusions, it is also slower and can be mentally taxing, requiring focus and concentration to function effectively.