This term refers to the limits on our brain to processing information. The number of items that can be held in short-term memory or that can be the focus of attention, as stated by George A. Miller in his 1956 paper. The number applies only to retention and recall of information, and not to recognition. Miller argues that the number of objects an average human can hold in working memory is 7 ± 2. This is frequently referred to as Miller's Law.

Also see: "The Magic Number Seven, Plus or Minus Two: Some Limits on our Capacity for Processing Information" (The Psychological Review, 1956, vol. 63, pp. 81-97).