An application server is a program designed to manage what the webserver cannot.  A webserver simply delivers web content - HMTL, images, etc.  It is not designed to manage anything else.

Yet, we had PWS running our ASP.  This works because PWS has a built-in Application Server that processes the ASP code.

The Apache Webserver does not come with a built-in Application Server.  That is what Tomcat is for.  Tomcat will process the Java code that we will be embedding into the HTML.