The Oracle Universal Installer (OUI) is used to install the Oracle Database software. OUI is a graphical user interface utility that enables you to:
View the Oracle software that is installed on your machine
Install new Oracle Database software
Delete Oracle software that is no longer required
During the installation process, OUI will start the Oracle Database Configuration Assistant (DBCA) which can install a precreated default database that contains example schemas or can guide you through the process of creating and configuring a customized database.
If you do not create a database during installation, you can invoke DBCA after you have installed the software, to create one or more databases.