Summary widgets usually are placed on a dashboard page and show counts of records from a custom FetchXML statement. For example. "# of Open Cases"
A grid can be mapped to a CRM View, with its corresponding columns, filters and sorting. Changes to the CRM View are reflected instantly in the portal
Or a grid can be defined a custom FetchXML statement to add dynamic filtering based on the logged in Portal user. FetchXML is creating using Advanced Find.
The calendar widget will display records from any CRM entity that can be found using Advanced Find provided that they have a "Start Date" and "End Date"
A portal form is mapped to a CRM Form and changes to the CRM Form are reflected instantly in the portal.