What is an Application server

What is an Application server

 An Application server controls the business logic. Separating business logic from web server and adding to application server will give more reusability for this logic across different applications. This is more flexible design.

A web transaction using app server will be like this as below,

Browser (click operation to display some results on a grid> ==> Request goes to web server (Apache HTTP server) ==> Application server (Tomcat server) ==> Database

Or

Browser (click operation to display some results on a grid> ==> Request goes to web server (Apache HTTP server) ==> Application server (Tomcat server) ==> Web service ==> Third party Database

Note: Web server related topic – please click on  What is Web server?