Portlets support three states - maximized, minimized, and normal. You can change the state of the portlet by clicking on the maximize 
, minimize 
, or restore 
(to return to a normal state) icons in the title bar of the portlet.
A portlet in maximized state expands to use the entire content area of the portal page. Some portlets support a different layout or additional content when the portlet is maximized.
A portlet in minimized state only displays the title bar.