Explanation/Reference:
Explanation:
When installed, the Oracle Preinstallation RPM does the following:
As needed, sets sysctl.conf settings, system startup parameters, and driver parameters to values

based on recommendations from the Oracle Preinstallation RPM program
Creates an oracle user, and creates the oraInventory (oinstall) and OSDBA (dba) groups for that user

Automatically downloads and installs any additional RPM packages needed for installing Oracle Grid

Infrastructure and Oracle Database, and resolves any dependencies
Sets hard and soft resource limits

Sets other recommended parameters, depending on your kernel version

Note: The Oracle RPMs for your Oracle Linux distributions and Oracle RDBMS releases automatically install any additional packages needed for installing Oracle Grid Infrastructure and Oracle Database, and configure your server operating system automatically, including setting kernel parameters and other basic operating system requirements for installation.
References: https://docs.oracle.com/database/121/LADBI/pre_install.htm#LADBI7493