Hi Manchikanti,
Have a look at another forum question: https://forum.mendix.com/link/questions/87264 Gives the difference between the Database replication and Database connector and when to use it.
If you are running your app on a Microsoft SQL server Database, and then attempt to connect to another Microsoft SQL server Database, you encounter an error where mendix attempts to load another instance of a JAR file used to establish the Database connection. Ticket has been submitted to mendix and a fix is planned for an upcoming release.