What's the difference between a lookup type and a value set?
A lookup type consists of lookups that are static values in a list of values. Lookup code validation is a one to one match.
A table-validated value set may consist of values that are validated through a SQL statement, which allows the list of values to be dynamic. The following table brings out the differences between a lookup type and a value set.
You can define a table-validated value set on any table, including the lookups table. Thus, you can change a lookup type into a table-validated value set that can be used in flexfields.
| 
                      Area of Difference  | 
                  
                      Lookup Type  | 
                  
                      Value Set  | 
               
|---|---|---|
| 
                      List of values  | 
                  
                      Static  | 
                  
                      Dynamic if the list is table-validated  | 
               
| 
                      Validation of values  | 
                  
                      One to one match of meaning to code included in a lookup view, or through the determinant of a reference data set  | 
                  
                      Validation by format or inclusion in a table  | 
               
| 
                      Format type of values  | 
                  
                      char  | 
                  
                      varchar2, number, and so on  | 
               
| 
                      Length of value  | 
                  
                      Text string up to 30 characters  | 
                  
                      Any type of variable length from 1 to 4000  | 
               
| 
                      Duplication of values  | 
                  
                      Never. Values are unique.  | 
                  
                      Duplicate values allowed  | 
               
| 
                      Management  | 
                  
                      Both administrators and end-users manage these, except system lookups or predefined lookups at the system configuration level, which can't be modified.  | 
                  
                      Usually administrators maintain these, except some product flexfield codes, such as GL for Oracle Fusion General Ledger that the end-users maintain.  | 
               
Both lookup types and value sets are used to create lists of values from which users select values.
A lookup type can't use a value from a value set. However, value sets can use standard, common, or set-enabled lookups.