Concept of information stores

Using attached ppt document and the below video link as a reference, explain the concept of information stores as they relate to email. Use the Internet to research how and where email data is stored on different computer platforms and systems and then report your findings. How is this information pertinent to a forensic investigation. 200+ words, references at the end must.

https://www.youtube.com/watch?v=GlBiuV90Djk