What's the Difference Between Retrieval and Refreshing Tasks?

What's the difference between a retrieval kind of opportunity or task? This is a review task. If something hasn't been revisited in a long time, do one of these review tasks to refresh your tasks. But then maybe a week later or something, then you follow it up with the appropriate retrieval task. And i would tell my students that, and i would be really explicit and say, you haven't done this in a very long time. So i'm not going to quis you because i know that it will take you a long time.