Question: What are the major differences between ASP.NET
and the older ASP technology?

Answer:

• Object-orientation. Whereas the old ASP technology simply
  allowed the programmer to mix HTML text with dynamically generated
  parts, ASP.NET is object-oriented. The web page and all the GUI
  elements on it are objects that can be configured, react to user
  input events and render themselves to HTML. There is a large number
  of prefabricated GUI objects that can be used on ASP.NET pages and
  the programmer can even write his own GUI objects.
• Event-driven model. ASP.NET pages are event-driven. Any user interaction
  such as a mouse click on a button raises an event that can be handled by
  the programmer. Thus programming ASP.NET web pages mainly requires the
  programmer to handle user input events, whereas
  generating the HTML that is sent back from the server to the client
  is completely taken care of by ASP.NET.
• Code-behind files. In ASP.NET the layout of a web page and the
  program logic behind it can be implemented in separate files. This
  allows web designers and programmers to work on their own files without
  having to deal with issues that they do not want to be bothered with.
• State management. When a web page is sent from the browser to
  the server and back again, the state of certain GUI elements (e.g.
  text boxes or check boxes) should remain unchanged. In ASP this has
  to be implemented by the programmer by writing the values of the old
  state into the GUI elements of the newly generated HTML stream. In
  ASP.NET the framework takes care of this. If the values of GUI elements
  are not explicitly changed by the programmer they remain unchanged.