Metadata for CDP geometry can be found in the 2010 Census Designated Place, 2010 TIGER/Line Shapefile Metadata, as well as in the 2010 TIGER/Line Shapefiles Technical Documentation.
This layer also includes demographic data for each place and Census Designated Place. These data come from the 2010 Census Demographic Profile Summary File. For more information on the specific variables/attributes included, view the table matrix section on page 4-21 in the Technical Documentation.
More on Census Designated Places (CDPs):