Backup is really important in the Oracle database field .
Backup is useful in the disaster recovery we can use the same backup for the recovery purpose .
there are different way to take the backup in the Oracle database .
we can take the Oracle backup as hot backup and cold backup
If the Oracle database is up and running then we can perform hot backup
Database should be in archivelog mode to take the hot backup
Hot backup will be inconsistent backup as the database is running while taking the backup and there is chances that database will be updated while the backup is going on
Could backup can be taken when the database is down
Database can be in noarchivelog mode while taking the cold backup
Cold backup can be consistent backup as the database will be down call before running cold backup.
Following video will give you the complete understanding of hot backup and cold backup in Oracle database field.