Heidi:

If you purchased Sage 50c, it is a combination desktop and cloud product. With Premium you may have 2 users using the product at the same time concurrently. You may store your data on a dedicated server and have 2 users access the data through a network at the same time. You may also have a peer to peer setup where one computer is the server and workstation and another accesses the data from another computer connected via a network. With the Remote Data Access (RDA) setup your data can put into cloud and again you may have a maximum of 2 concurrent users access the data at the same time.

Hope this helps!