| Connected lookup | Unconnected lookup |
| Can use static or dynamic cache | Uses static cache |
| Input is directly received from a pipeline | Input is received as a result of a :LKP expression in some other transformation |
| Provides support for user-defined values (default) | No support for default user-defined values |
| If there are no matching results for the lookup condition, the service returns a default value | A NULL value is returned if there is no match |
