Here is the difference between the ORACLE_HOME and ORACLE_BASE.
Both ORACLE_HOME and ORACLE_BASE are the directories which are located in OFA (Oracle Flexible Architecture) from which the ORACLE_BASE is the Home/Root/Top level directory and the ORACLE_HOME is located beneath the ORACLE_BASE directory where the oracle products reside or we can say that ORACLE_HOME is the subdirectory of ORACLE_BASE.
ORACLE_BASE includes the multiple oracle products and ORACLE_HOME specifies the directory containing the oracle software for a given release.
The value recommended for an OFA configuration is
software_mount_point/app/oracle.
For example: /u01/app/oracle.