The concept of flow, as introduced by Mihaly Csikszentmihalyi, refers to a state of complete absorption in an activity where the skill level and difficulty of the challenge are matched. This state is characterized by heightened focus and concentration, often described as being "in the zone". To feel challenged, individuals can pursue three types of challenges: increasing their skill level in an area of existing expertise, building new skills in unfamiliar areas, or finding opportunities that simulate a challenging workload. The key to experiencing flow is finding a balance between challenge and skill level, as exceeding this balance can lead to anxiety, while underestimating it can result in boredom.