كيف يمكن عمل نسخة إحتياطية من الاوراكل ابليكاشن

you can use offline bakup .

shutdown the application and take the bakup you need which platform u use windows or unix

How to backup a file/directory ?

This is most common & very basic thing in taking backup, backup is snapshot of any file at a particular time . In order to take backup of file/directory so that it can be recovered at later stage (In case of any issues)
cp filename filename.bak
If you want to backup directory you can use
cp -R dir dir.bak
If directory is quite big lets assume APPL_TOP which is around 11GB you can tar (zip) utility in linux.
tar -cvf dir.tar dir ( Where -c is compress , v is verbose, f is file )
to restore backed up directory use -x extract option like
tar -xvf dir.tar

How to backup a table ?
If you are a DBA you will find this bit silly but you can use create table as assume you want to backup table FND_USERS to table FND_USERS_BAK , you can use
SQL> create table FND_USERS_BAK as select * from FND_USERS;
Though you can use imp/exp feature of database as well to backup a atble.

What are two main backup categories for Database ?
Broadly you have Cold Backup & Hot backup option with database.

Cold backup : is database backup which you take when database is down
Hotbackup : is database backup during which database is available to user . For Hotbackup database should be in archive log mode. Tablespaces should be in begin backup mode while copying data files.

Advantages of Cold backup :
Easy to implement, No need to convert database in to archive.
Disadvantage of Cold Backup :
Services are not available during backup, not acceptable in production

Advantages of Hot backup :
Users can access database & application during backup
Disadvantages of Hot Backup :
Difficult to implement initially, extra space for archive logs

For Cold Backup of Database & Applications :
--Shut down application tier services using adstpall.sh
--Shutdown database listener & database
--Copy file system (middle Tier & Database tier including software & datafiles to tape or harddisk ). You can zip or tar as well to reduce size of backup as mentioned above via tar -cvf
--Once backup is over start database & db listener
--Start Application Tier

For Hot backup of Database & Applications :
--Make sure database is in Archive log mode ( How to check & how to convert coming tomorrow)
--Put tablespaces in to begin backup Mode
--Create backup control file
-- Copy datafiles , log file, control files
--Put tablespaces into end backup Mode
-- Copy oracle software & middle tier software as mentioned in cold backup mode
Backup done