A portal page is made of a set of portlets. For example, the portal page such as Welcome contains portlets such as Navigation, Language, and so on And the portlet Language has icons (such as Look and Feel, Configuration, Minimize, Maximize, and Remove), title icon and title (such as Language), and a window which may contain contents (such as a set of language icons and links).
In a normal way, a portlet is an application that provides some content (such as information or service) that forms part of a portal page. A portlet container handles the portlets. A portlet container also processes requests and generates dynamic content. Actually, portals use portlets as pluggable user interface to provide a presentation layer information.