Using the 4D Open for 4D routines, a single client machine can open multiple connections to several 4D Server databases at the same time. Each connection to a 4D Server corresponds with a unique 4D Server process created for this purpose.
With 4D Open, each client can open six concurrent connections (processes) to the same server. After the sixth process has been opened with OP Open connection, an additional user license is consumed to accommodate up to six additional connections, and so on.
It is important to note that each and every connection from a different 4D Open client will consume a whole client license on a 4D Server. Even though each client can open up to six connections as described above, this is only if the multiple connections are coming from the same client. The maximum number of concurrent users is determined by the 4D Server licenses which you have purchased.