Short-term memory (or "primary" or "active memory") is the capacity for holding a small amount of information in mind in an active, readily available state for a short period of time. The duration of short-term memory (when rehearsal or active maintenance is prevented) is believed to be in the order of seconds. A commonly cited capacity is The Magical Number Seven, Plus or Minus Two (which is frequently referred to as Miller's Law.) In contrast, long-term memory can hold an indefinite amount of information. Short-term memory should be distinguished from working memory, which refers to structures and processes used for temporarily storing and manipulating information (see details below).