DUNNS NUMBER: 
A data universal numbering system or DUNS number is a unique, nine-digit series of numerals that identifies a business
 
UEI NUMBER: 
A Unique Entity Identifier (UEI) is a 12-character, alpha-numeric code assigned by the U.S. General Services Administration (GSA) to individual businesses applying for grant money, or government assistance
 
Cage Codes
The Commercial and Government Entity code, a unique identifier assigned to suppliers to various government or defense agencies. A standardized method of identifying a given facility a specific location