Curiosity about workspaces

When I reload a workspace, is it loading from a backup file or from the database? For example I have two packages and several queries open and I create a workspace and go home for the day. When I come back I reload the workspace. Now I make dozens of changes, debugging, reworking etc. I know I can resave the workspace, but if I make changes, compile, save to disk etc., but forget to re-save the workspace, what does the workspace load from? Is there the potential to reload obsolete code?