Microsoft's CWS is basically a cloud-in-a-box. That sounds like a contradiction, but bear with me. Here is its datasheet:
Microsoft basically integrates a bunch of its software, including Windows Server, System Center to manage it, the Azure Pack to extend it, and it all runs on Dell servers, storage and networking gear. IBM and Dell had similar offerings for several years.
AWS doesn't have any on-premises equipment: they truly are a cloud platform that is running in their datacenter, not yours.
If you already are familiar with Windows Servers and have applications running on them, CWS is a good first step towards moving them into someone else's cloud datacenter. If you are using something else, then this isn't the right direction for you.