Consistent Database Export of Oracle Database
Data Pump command-line arguments are partially backward-compatible with Export and Import utilities, and CONSISTENT maps to FLASHBACK_TIME.

FLASHBACK_SCN is used to specify system change number until all changes from the source database are exported. FLASHBACK_TIME allows you to specify change time. When you specify CONSISTENT, Data Pump Export determines the current time and uses that value for FLASHBACK_TIME implicitly.

For more info read Oracle Database Utilities.