For current Oracle databases, Data Pump is the preferred way to export a schema. The older exp/imp utilities are legacy tools and are mainly relevant to older environments.
Export a schema with expdp
expdp system@database \ schemas=SCOTT \ directory=DATA_PUMP_DIR \ dumpfile=scott_%U.dmp \ logfile=scott_export.log
The Oracle directory object points to a server-side filesystem location. The database user running Data Pump needs the required privileges on that directory object.
Import the schema
impdp system@database \ schemas=SCOTT \ directory=DATA_PUMP_DIR \ dumpfile=scott_01.dmp \ logfile=scott_import.log
Data Pump exports are logical exports, not a replacement for RMAN or storage-level database backups. Use the right backup method for the recovery objective.
Legacy exp
The classic exp command may still exist in older Oracle environments, but new procedures should generally use expdp/impdp.