Portlet Container

• The lifecycle of a portlet is managed by the portlet container. A portlet container runs portlets and provides them with the required runtime environment. A portlet container contains portlets and manages their lifecycle. It also provides persistent storage for portlet preferences. A portlet container receives requests from the portal to execute requests on the portlets hosted by it.
• A portlet container is not responsible for aggregating the content  produced by the portlets. It is the responsibility of the portal to handle the aggregation
• A portal and a portlet container can be built together as a single component of an application suite or as two separate components of a portal application.
• The portlet container is an extension of the servlet container. As such, a portlet container can be built on top of an existing servlet container or it may implement all the functionality of a servlet container. Regardless of how a portlet container is implemented, its runtime environment is assumed to support at least Servlet Specification 2.4.