THIS IS THE EXPLANATION!
The Multi-Store Model is an example of an information processing model, meaning that information is processed in stages. In the Multi-Store Model every single thing around you goes into your sensory memory, it is input and then encoded. Then the bits of information which you pay attention to are transferred to your STM and then if it is rehearsed there then it is transfers to the LTM. If it is not rehearsed then it is output and will be forgotten. Once information is in the LTM if you want to use it then you need to retrieve it, however you do not retrieve the original memory trace more a copy of it so that if it isn't rehearsed then the original is still in the LTM.
STM-7+/- Items at a time for 0-30 seconds if not rehearsed LTM-Unlimited capacity and unlimited duration