This is a Do it yourself jobby..
Think it as leasing a server and you can configure it as you please..
Software, hardware, storage, literally everything..
Its prepaid, you then buy credits. Though the more credits you buy in bulk the discount then become massive.. 35%..
You then are charged credits based on your configuration.. You up the configuration your charged more, etc etc
The beauty is its adjustable as anytime.. I can even temporarily create a second server to run alongside if need be.. Which will be useful for the upgrade..