Import and Export Database

Using Exp?
C:\>Exp system/manager@orcl FULL=y file=c:\system.dmp Log=c:\system.log

Two user with multiple tables
EXP SYSTEM/password FIlE=C:\expdat.dmp TABLES=(scott.emp,hr.countries)
Single user
EXP scott/tiger FILE=dumptables.dmp TABLES=(emp,dept)

Using Imp?
Import Full database
imp SYSTEM/password FULL=y FIlE=C:\dba.dmp
To import just the dept and emp tables from the scott schema
imp SYSTEM/password FIlE=C:\dba.dmp FROMUSER=scott TABLES=(dept,emp)
To import tables and change the owner
imp SYSTEM/password FROM USER=blake TOUSER=scott FILE=blake.dmp TABLES=(unit,manager)