CONTENT parameter is used in expdp or impdp, to load/unload data only, metadata only or both.

CONTENT
Specifies data to unload.
Valid keyword values are: [ALL], DATA_ONLY and METADATA_ONLY.

CONTENT=ALL is the default value

CONTENT=METADATA_ONLY:

It will take export only the metadata, i.e skeleton/DDL on the object/schema. It won’t export any of the data/rows.

dumpfile=emp_enc1.dmp 
logfile=emp_enc.log 
directory=VEN 
tables=DBATEST.EMP_TAB 
CONTENT=METADATA_ONLY

Connected to: Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options
FLASHBACK automatically enabled to preserve database integrity.
Starting "SYS"."SYS_EXPORT_TABLE_01":  /******** AS SYSDBA dumpfile=emp_enc1.dmp logfile=emp_enc.log directory=VEN tables=DBATEST.EMP_TAB CONTENT=METADATA_ONLY
Processing object type TABLE_EXPORT/TABLE/TABLE
Processing object type TABLE_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS
Processing object type TABLE_EXPORT/TABLE/STATISTICS/MARKER
Master table "SYS"."SYS_EXPORT_TABLE_01" successfully loaded/unloaded

CONTENT=DATA_ONLY:

It will take export only the ROWS/DATA of the tables, by excluding the DDL(i.e metadata)

dumpfile=emp_enc2.dmp 
logfile=emp_enc.log  
directory=VEN 
tables="DBATEST"."EMP_TAB" 
CONTENT=DATA_ONLY

FLASHBACK automatically enabled to preserve database integrity.
Starting "SYS"."SYS_EXPORT_TABLE_01":  /******** AS SYSDBA dumpfile=emp_enc2.dmp logfile=emp_enc.log directory=VEN tables=DBATEST.EMP_TAB CONTENT=DATA_ONLY
Estimate in progress using BLOCKS method...
Processing object type TABLE_EXPORT/TABLE/TABLE_DATA
Total estimation using BLOCKS method: 23 MB
. . exported "DBATEST"."EMP_TAB"                         19.16 MB  175340 rows
Master table "SYS"."SYS_EXPORT_TABLE_01" successfully loaded/unloaded
******************************************************************************
Dump file set for SYS.SYS_EXPORT_TABLE_01 is:

Before importing the dump into another database, make sure that the table exists in that table, as we have taken export using DATA_ONLY,
which don’t contain the DDL. Else import will fail with an error as below.

Here we tried to load this dump into a database, where table doesn’t exist.

select table_name from dba_tables where table_name='EMP_TAB';
 
no rows selected

Master table "SYS"."SYS_IMPORT_FULL_01" successfully loaded/unloaded
Starting "SYS"."SYS_IMPORT_FULL_01":  /******** AS SYSDBA dumpfile=emp_enc2.dmp logfile=emp_enc.log directory=VEN
Processing object type TABLE_EXPORT/TABLE/TABLE_DATA
ORA-39034: Table TABLE_DATA:"DBATEST"."EMP_TAB" does not exist. ---- >>>>>>>>  ERROR 
Job "SYS"."SYS_IMPORT_FULL_01" completed with 1 error(s) at Tue Jan 24 14:45:01 2017 elapsed 0 00:00:54

So it failed.

NOTE – NEVER USE TABLE_EXISTS_ACTION=REPLACE