How to Publish the project which was edited by different user.

Some users doesn't have permission to publish the project & they edit the projects and checkin the project. When I open the project from his machine I see the changes & when I open the project from my machine I don't see the changes. is there any place the draft projects will save? does administrator has to publish the project so other users can see the project changes?

Please let me know if you need additional information

I am still learning Project server 2010......It is completely different from SharePoint

Thanks in advance.... :)