At first, this seems like a distinction without a difference. But, of course, then it seems like two totally different things. A status report communicates stasis. It shows what is true at a certain time. A progress report communicates time. It shows what's happened (and even might preview what's going to happen). So, is one better than the other? Not really. But, it's important to realize that each one places emphasis in a different area. The status report stresses achievement. It can be shorter. So, it's useful for an executive audience. The progress report stresses events. It is longer. It shows what has happened, and is thus useful as a sort of historical record. It's useful to a project manager---in order to see what's gone on to lead us to this place. I suppose the best report might combine both. This is where we are, and this is how we got there.