Working memory (WM) is the system which holds multiple pieces of transitory information in the mind – information that is needed for different tasks right now. Working memory differs from short-term memory in that it is the storage and manipulation of information, while short-term is solely the storage of information in a readily available state. Therefore, short-term memory is a component of working memory. Working Memory capacity is usually assessed by determining the number of pieces of information a person can hold in mind. For example, a person might be asked to listen to a series of digits and letters, sort them into order in mind, and then recall the sorted list aloud. The longest set of characters or other items that can reliably be recalled is the working memory capacity.The capacity of working memory differs between people: a person able to recall 8 instructions has a greater working memory capacity than someone who can only recall a series of 5. Numerous scientific studies have linked working memory capacity with strength in other fundamental cognitive abilities, including attention and intelligence.