The Lookup transformation is used to look up a source, source qualifier, or target to get the relevant data. You can look up flat file and relational tables. The Lookup transformation works on similar lines as the joiner, with a few differences. For example, lookup does not require two sources. Lookup transformations can be connected and unconnected. They extract the data from the lookup table or file based on the lookup condition.
Perform the following steps to create and configure a Lookup transformation: