There are three sets of objects, (1) the current edit content, (2) the draft, which is a copy of the current edit content, and (3) the fully saved and committed profile content. When you first start an edit session, all three objects are the same. When you make a change the current contents no longer match the other two (but the draft and profile still match each other until the first draft save). Once you do a draft save (auto or manual), the current edit session will equal the draft but the draft no longer matches the actual profile contents. After the draft is saved, any future changes in the edit session will make the edit contents differ from the draft until the next draft save. A full save will commit the current edit session contents (not the draft) to the profile and any draft is deleted.
One can see the current differences between the latest draft and the profile by clicking the link "compare draft with saved information' that is found below the 'save draft' button. Nota Bene: this does not show the current differences between your edit session and the draft (or the edit session and the profile for that matter - although one can save the contents to the draft before clicking the link to effectively see any changes since the start of the edit session). PS, if using the Web Browser Extension an access key can be configured for use instead of clicking on the link.