Part and Color Combination (PCC) is BrickLink's name for the Element ID used by the LEGO Group to identify a specific part in a specific color. PCCs can be found in the parts list in set instructions after 2007. This number is unique for a part and color combination and should not be confused with an item number, which is a unique number of the mold.
The same part in the same color can have several PCCs. These may be viewed on any catalog entry for parts by clicking the Color Images link to the left of the image. It is also possible to search the catalog with a PCC number to locate the specific part and color combination.