A "performance monitor" will typically tell you how well an application is performing. For example, it might tell you requests per second. A profiler will tell you how long it is taking your app to service a request, and how often it services certain types of requests. This can usually be broken down all the way to the individual methods. For example, how many time method X was called and the average/maximum/minimum amount of time spent in method X. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4162614#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...