Plone portlets are special-purpose content objects meant for presenting information useful across multiple pages on the site, like news and site-wide guidance. If you have sufficient (site mananger) permissions, you will see a "manage portlets" link at the bottom of each portlets column, which brings you to a page where you can add, remove, and adjust the ordering and settings for each portlet.
Pages and folders typically inherit their portlets arrangement from their containing folders, and they offer controls to augment or replace the collection, per column.
the name "portlet" derives from the technical name for a plone site, a "portal". the arrangement of portlets was originally shared across all pages on a site. in the current incarnation, portlets can be specific to pages within a section or even individual pages, as well as shared across the site. people with site management privileges can adjust the portlets assigned to a section of the site, edit assigned portlets, and change their organization across the site in elaborate ways.
When logged in with management privileges, you will see a manage-portlets link at the bottom of the portlets, if any, in the right- and left-hand side columns. These links take you to portlet configuration pages for the current page/folder context. Here are instructions for using these facilities:
- Portlet Hierarchy - describing how portlets are inherited by contained pages from containing folders
- Arranging Portlets - adding, removing, and adjusting portlets
- Portlet Types - we primarily use only a few portlets, but not necessarily the ones described there.