What is an application server?

I've worked on the .Net platform for last two years and now I'm moving on to .NET Web development.

I am confused about the Application server. What is it ? What are Roles? How is it different from the Web server?

In Windows is there any Application Server program like Tomcat with Apache Server? I read Wikipedia and MSDN, there is no any clear documentation regarding Application Server. So please advise me where I can clear my doubts. Is there any good link?

.net .net, application server 0 Answer