My short answer is, don't care about the difference. Just press <F9> when you want to create an album, jAlbum will do the right thing for you. That's what I do for more than a decade now. But you'll get a good explanation from the usual suspects anyway.
Make album = The button to press in 99% of cases
Make changes = Process pages but only process newly added images. Only meant for testing various effects of skin changes as its far quicker, but can produce unmatched image sizes (stretched or shrunk images). These days this option is actually called Make Test to better reflect its purpose.
Make all = Reprocess all pages and images. Now relabeled "Fore remake". Doesn't try to figure out what changes that have been made. Not used much today as "Make album" is so clever in figuring out the minimal amount of images (and videos) to re-process. I use this option when studying image scaling performance though
The dangerous option is Force Remake (used to be Make All). It forces jAlbum to reprocess all the images, whether it needs to or not. If you have a project with a lot of videos, you can be in for a long wait while it regenerates all of them. Even on a high-end machine that can take a long time, and on a laptop, you could probably fry an egg on the case.
The other thing to remember about Force Remake is that all of the images and videos in the finished album will have new timestamps, which means they'll all get uploaded again, even if they haven't really changed.