A4J Region and OutputPanel

[kewldude]

Okay, this is a very simple question for the a4j gurus out there. I hope you have time to answer this.

Ive read the usersguide for ajax4jsf. I'm jsut a little bit confused between a4j:region and outputpanel.

I just want to know in layman's term whats the difference between a4j:region and a4j:outputpanel and when to use and when not to use the said components?

[ilya_shaikovsky]

a4j:region - limits the tree to be processed on ajax request.

a4j:outputPanel - marks zone to be reRendered after the ajax request. It shuld be used to reRender the zone instead of specifying concrete component. Also it can be made updatable always by using ajaxRendered attribute.