Office 365 is a cloud based implementation of Microsoft’s functional and collaborative Office Suite. It is designed to also interact with mobile devices as well as providing “thin client” capabilities for business PCs.   Below are some key resources: 

Office 365 – Home Page

Office 365 – Press release

Office 365 – Overview

Microsoft Online Services Trust Center Information

Office 365 – Articles

Office 365 – Product Reviews,2817,2383731,00.asp