What would be the features of a cloud based web application

Question

I am going to build a very sensitive cloud based application , but before that i just want to get it know how a simple websitea nd cloud based website are different to each other what are the core things which we should consider while creating a cloud based web applications , basically my system contains very secure data like banking information how do i ensure that it is secure i am using ASP.NET as platform any suggestions are welcome and appreciated .

 suggest all things which i should care about 

 

 

Thanks