Parameters

Go to Admin->Content->Article Manager. You will see these icons for actions related to articles.

Most things in Joomla! (such as articles, menus, modules and components) have Parameters associated with them. These Parameters are options so that the behavior of individual items can be fine tuned.

Go to Content->Article Manager. In the row of icons is one called parameters. Clicking on this brings up the "Edit Parameters" screen. Here you can set global parameters for all articles. Individual articles can override the global settings.