One great thing when using SQL Server, or an application which consumes a database on SQL Server, is that you can get the data from another server and/or database. One such example would be displaying reference data from another database.
The following link shows the naming conventions in MS SQL Server:
The most important thing here is 4-part naming convention where you simply add servername.database.schema.table into a query, referencing remote data.
Before that is possible, however, it is required to add a linked server and provide proper authentication and authorization to the calling server.