I am a little confusing about the default catelog setting..

When I add a new item into the store. It will display the short description. When I click the picture, I found the detail display, but the short description still show under the detail description.

Can somebody introduce how to setup the catelog for general using?

What are the setting's mean in the setting page. It look like we can use multiple catelog module at the same time to do some special display purpose. But how should I used it?

Thank you~~

I wish I can build a good look of the store.(Of course I need to modify the template.) But I am looking for more information about how to do it.