Web Apps
Web applications refer to programs that are available over the Internet.  This term is actually very loose, and different people will have different ideas of what is and what isn't a web applications.

Some people will claim that if somthing being served over the web that allows you to interact with it is a web application.  Others will tell you that it's not a web application unless it's web service driven and performs some sort of business process function.

I tend to sit in the middle.  I know a web application when I see one.  If you were to ask me what makes it a  web application, I would probably just tell you "Because it is," but I know in my heart that it is a web application.

I have been struggling with my definiton lately though because of Content Management Systems(CMS) or Portals as their know.  Are they actually web applications?  Once again that's a matter of opinion.  Certainly many of the CMS systems out there have pass the barrier of boring web site into the realm of web application, but where is the line drawn?

One of the biggest problems with judging CMS systems as web applications is that the admin or back end of the CMS system really is a full blown web application, but the front end is still just a boring old website, at least from a technical stance.

I think there should be more effort into making that front end a web application with interactivity. Determining the best way to make this happend is still a mystery though.  Who ever figures it out will own the web in the future.