The type of list being returned within the web part.
Options:
•Announcements - Announcements list
•Contacts - Contacts list
•CustomGrid - Custom grid for a list
•DataSources - Data sources for a site
•DiscussionBoard - Discussion board
•DocumentLibrary - Document library
•Events - Events list
•GanttTasks – Tasks list with a built-in Gantt display
•GenericList - Custom list
•IssueTracking - Issue tracking
•Links - Links list
•ListTemplateCatalog - List Template gallery
•PictureLibrary - Picture library
•Survey - Survey
•Tasks - Tasks list
•WebPageLibrary - Wiki Library
•WebPartCatalog - Web Part gallery
•WebTemplateCatalog - Site Template gallery
•XMLForm - XML Form library