Mobile headache

Question

is Mobile web application = Mobile application??? Currently i am working on mobile medical application project and i know that the result will be creating a mobile website that allows mobile phone (client-side) to perform some action, for example making registration for consultancy with doctor. But at the same time, there is a receptionist at the server side (mobile website) monitoring every action performed and may respond to the actions by sending message back to the client. This two-way communication is what i want in my application.....is it possible or is this making sense for mobile medical application??? any topic or reference book (especially mobile C#.NET) you can suggest for me to refer to. I really hope that i can code for client side and server side in order for both sides responding to each other. THANK YOU.