The Multi-User Edition enables you to let more than one person work on the database at the same time. You'll need to have a computer that can run the server software as well as your users' computers. The basic installation comes with two user licences; you can add as many addiitonal user licences as you need. Note that when ordering, choose the platform that the SERVER will be running on. Your users can be running on any mixture of Windows and Macintosh computers.