What is the purpose of catalog in raman?

[Pham1990]

Hi I am a little unsure of the purpose of catalog in rman. I know channel basically contain metadatas for backup but why do we need them vs just doing rman> backup database plus archivelog?

[gandolf989]

You can get by without an RMAN catalog just fine. If you choose to use one, it will contain a record of every backup, the type of backup, and when it was run. It does not track the name of the server where the backup was run. I find that odd. But that is what it does.