If you use original Export (exp) and Import (imp), then you may have scripts you have been using for many years. Data Pump provides a legacy mode which allows you to continue to use your existing scripts with Data Pump.
Data Pump enters legacy mode when it determines that a parameter unique to original Export or Import is present, either on the command line or in a script. As Data Pump processes the parameter, the analogous Data Pump Export or Data Pump Import parameter is displayed. Oracle strongly recommends that you view the new syntax and make script changes as time permits.
The Data Pump Export and Import utilities create and read dump files and log files in Data Pump format only. They never create or read dump files compatible with original Export or Import. If you have a dump file created with original Export, then you must use original Import to import the data into the database.
You should understand the following topics before using Data Pump legacy mode: