Help: Name confusion.

Hi!

I am very confused. Can anyone tell me the diffenrence between an instance and SID name.
When I installed my server I was asked to input an SID name and I chose the default name "ORCL", and now when I look in the v$database view, I am told that my database is called oracle. What is the diffenrence and what is the names used for?

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Casper Thrane
System developer
Benau A/S