Totally confused by Re-Check vs Save For Later

Hi, I am adding some actor and crew credits on my film and tweaking a few credits here and there, but I'm very confused - I have been clicking Save For Later, but then I get a message saying "if you would actually like to submit your changes this is your reference number". So have my changes not gone through then ? Because when I click that reference number it just goes to my edit page and I've no idea of any of my changes have been made. So do I need to do them all again and this time click Re-Check ? It's so needlessly complex - can anyone clarify for me please ? Thanks.