All users are going to work in the same office.

To access Sage 50 from the same office, install Sage 50 on all computers that require access to the company file. Each computer must also have the necessary permissions to access the server folder. After installing Sage 50 on each computer, share the company files over the Local Area Network (LAN)

Users are going to work from different remote locations.

To access Sage 50 from different remote locations the company must be shared using Sage's Cloud Connected feature, Remote Data Access (RDA). RDA makes your Sage 50 company accessible from any computer with a reliable internet connection and Sage 50 installed. See How to share a company data file using Remote Data access (RDA).