The concept of "7±2" refers to a theory proposed by psychologist George A. Miller in 1956, which suggests that the average number of objects an individual can hold in working memory is about seven, plus or minus two. This means that most people can comfortably remember between five and nine items at a time. This idea has significant implications in various fields, including cognitive psychology, education, and user interface design. For example, when designing websites or apps, keeping the number of options or choices within this range can enhance user experience and improve information retention.