An application with administrative settings for each installation?

Just looking for some general information about it. What I want to do is create an application that can be installed on multiple pages. This application is the configurable settings for each unique installation.

For example, discussion, lets just say show this application, together with image and text. I want the admin (s) can modify the image and text on the page's application.

So I have some questions:

1. is it possible?
2. you can give a general orientation that head to complete this action? I guess you have to define my own database and somehow create a table in the database each time the application is installed? I could be totally wrong here.

I appreciate any help!!smile