Difference between multiple databases, multiple instances, and multiple installations?
In Oracle database terminology, an instance is the combination of background processes and memory structures that allow the user to access data in an Oracle database. In an applications context, instance and database are often used interchangeably.Multiple installations, or "installs" means that Oracle Applications are installed multiple times on a single database.Multiple databases or instances refer to a scenario in which there may exist numerous databases, each with one or more installations and implementations of the Oracle Applications.