Database or table rotation keeps a limited set of information (e.g. 3 months) available at any time. Let's call them month 0, 1, 2. As soon as you get to month 3, month 0 is dropped. The data is gone. I wouldn't recommend this with table or record archiving. It's good for throw-away data like ECC queue or sent/received email.

I have not used table extension in conjunction with table rotation so I cannot speak to it.