What is the object key before applying OSS Note

HI,

Anybody can guide me what is <b>object key</b>,is it need while applying an oss note using note assintant.<b>is it same as SSCR key</b>?,please clear my doubts and difference between SSCR key and object key, if possible can i get definition for object key.

Thanks and Regards,

vijayakumar