Mash up List Web Parts can provide an aggregation and connection between SharePoint Lists. Two or three Lists can be mashed-up to display an aggregated result of related information across these lists. One list would be defined as a parent list and the other one or two lists as the child lists. A column from parent list can be used to build the relationship with the child lists. Once the relationship is established, the resulting display can contain any columns from these lists (parent or child lists). For example, Customer list (parent list containing information like customer name, address and phone number) can be mashed up with Contact Lists (a child list). All the contacts for a company can be grouped and displayed below the Company details.