This is the Evaluation panel in the Security tab of the Publication Properties dialog:

This allows you to create an evaluation copy of your publication and set the number of days it will run before it expires. When the expiry date is reached, you can set the page that will appear on screen. Once the expiry date is reached, the user cannot run the publication unless you have included a Change Publication Evaluation action to the page you have entered in the Go to this page… option above.