I'm looking for an article or tutorial (or a couple of them) that would explain Microsoft's Exchange Server and its functionality plainly and with clear examples (what it does? why and when is that functionality needed? etc.), as for a layman if possible. I've looked over Microsoft's website, but it's nothing really specific. It seems that it presents a lot of business terms, but no clear examples or functionality.
I have no previous experience with MS Exchange, but I may be developing for it in the near future, that is why I would like to know what it is capable of and why it is needed within a company.