If a VB.NET program requires database input, or any other processing (maybe it gets information from some other computer in the network, for example), this is where it happens. But once everything is complete, the results of the VB program are combined with the result of processing the regular HTML and sent back to the client. Here's where another of the advantages of ASP.NET can be seen. Normally, the HTML that is sent back to the client is version 3.2 - probably the most common version of any - for maximum compatibility. In addition, ASP.NET controls can send HTML that is appropriate for a given browser. This means that code will work on older browsers just fine, but will also benefit from features available on new browsers.
Another advantage is that ASP.NET will maintain what is called "state" automatically when required. Ordinary web pages are "stateless" which means that the web server doesn't save any information, called "state information", about the web page between requests. But if you need to know the value of something between web pages, like an account number, ASP.NET can automatically keep track of it. (ASP.NET knows that our simple example doesn't require state information so nothing is created for this page.)
But, of course, we haven't actually done much that is very impressive yet. That's why the next lesson jumps right into the ASP.NET server based processing. The move from client side to server side processing in ASP.NET is the critical .NET difference!
