Types of Oracle Database Backup.

A)Whole or Partial Backups:
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The entire database or just a part of the database can be backed up. A whole backup is the backup of all the datafiles, the controlfile and spfile(If it is using). A partial backup will include one or more datafiles and/or the controlfile. Partial backups are valid only if your database is in archivelog mode.

B)Full or Incremental Backups:
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Full backups are backups which include datafiles in their entirety. It may be whole or partial but a complete copy of one or more datafiles.

An incremental backup is a backup of just some of the blocks of a datafile: only the blocks that have been changed or added since the last full backup will be included.

C)Consistent or Inconsistent Backups:
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Consistent backups are those created when the database is in a consistent state, that is, when all changes in the redo log have been applied to the datafiles.A consistent backup can only be created after a consistent shutdown, that is, not after a crash or a SHUTDOWN ABORT.A consistent backup can be opened immediately, without undergoing media recovery.

An inconsistent backup is a backup taken while the database is open. When a database is restored from an inconsistent backup, it must undergo media recovery, so that the database can apply any pending changes from the online and archived redo log before the database is opened again. Because archived logs are required for media recovery, using inconsistent backups requires that your database be run in ARCHIVELOG mode.

D)Image Copies or Backup Sets
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An image copy is a backup of a file that is byte for byte the same as the source file.

A backup set is a proprietary structure generated by RMAN. It is a logical structure
consisting of one or more physical files, known as pieces, which contains one or more
database files, which may be datafiles, controlfiles, or archive log files.