Data Pump jobs manage the following types of files:
Dump files to contain the data and metadata that is being moved.
Log files to record the messages associated with an operation.
SQL files to record the output of a SQLFILE operation. A SQLFILE operation is started using the Data Pump Import SQLFILE parameter and results in all the SQL DDL that Import would be executing based on other parameters, being written to a SQL file.
Files specified by the DATA_FILES parameter during a transportable import.
An understanding of how Data Pump allocates and handles these files will help you to use Export and Import to their fullest advantage.