SharePoint 2010's Summary Link Web Part
The Summary Link Web Part is one of three Web Parts provided by SharePoint 2010's publishing sites to display content. Although the Content Query and Table of Contents Web Parts let you configure a query to display items, the Summary Link Web Part allows you to manually select the items that you want to display. These items can link to pages in the site or to external sites.
Like the Table of Contents Web Part, the Summary Link Web Part is in the Navigation category. Unlike the Table Of Contents and Content Query Web Parts, the Summary Link Web Part doesn't have special configuration items in the Web tool pane. Instead, you add items directly to the Web Part and then manually select how you want them presented and ordered.
Summary Link can also be added to a page layout as a field control. This approach stores your links with the page, instead of inside the Web Part.
The Summary Link Web Part has a toolbar along the top, with these four options:
New Link: Click this button to link to a new item in the Web Part. You can link to a page, item, or person. You can also link to content outside SharePoint.
New Group: Create a new group that you can use to group the links you add to the Web Part.
Configure Styles and Layout: Select the default style that's applied to new links or change the style on all links you already entered into the Web Part.
Reorder: Move the items in the Web Part up or down to change the order.