Do Aliases create SEF URLs?

Just an explanation please  I understand that SEF Advance re-directs old URLs to the new format that is search engine friendly. Does this work the same where we use aliases ? A simple explanation would be helpful if you have time. Thanks

If you setup an alias for a URL then clicking on the old SEF URL would redirect you to that alias URL.

thanks for the explanation. will search engines treat the URL that has come from an alias the same as or differently from an SEF-generated URL ? In other words is there any advantage/disadvantage with either method ? thanks