Both, in a read-only ORACLE_HOME and read/write ORACLE_HOME, the user-specific files, instance-specific files, and log files reside in a location known as the ORACLE_BASE_HOME.

In a read/write ORACLE_HOME, the ORACLE_BASE_HOME path is the same as the ORACLE_HOME directory. However, in a read-only ORACLE_HOME, the ORACLE_BASE_HOME directory is not co-located with ORACLE_HOME but is located at ORACLE_BASE\homes\HOME_NAME.

Where, HOME_NAME is the internal name for ORACLE_HOME.

For example, the networking directories network\admin, network\trace, and network\log are located in the ORACLE_BASE_HOME directory. In a read/write ORACLE_HOME the networking directories appear to be in ORACLE_HOME because ORACLE_BASE_HOME is co-located with ORACLE_HOME, whereas in a read-only ORACLE_HOME the networking directories are located in ORACLE_BASE\homes\HOME_NAME.

set ORACLE_HOME C:\app\oracle\product\19.0.0\dbhome_1
cd ORACLE_HOME\bin
orabasehome

orabasehome
C:\app\oracle\homes\OraDB19Home1