Today, many theorists use the concept of working memory (WM) to replace the concept of Short Term Memory. This new model of STM “shifted the focus from memory structure to memory processes and functions”. To put it another way, WM refers to both structures and processes used for storing and manipulating information.
To sum up, STM refers to the ability to hold information in mind over a brief period of time. As concept of STM has expanded and it includes more than just the temporary storage of information, psychologists have created new terminology, working memory. The term WM is now commonly used to refer to a broader system that both stores information and manipulates it. However, STM and WM are sometimes used interchangeably.